A top Iranian military commander made a rare public appeal for forgiveness on Sunday as security forces fired on protesters and outrage over the mistaken downing of a jetliner reignited opposition on the streets and stirred dissent within the government’s conservative base.

It was the second day of protests after the military acknowledged early Saturday that it had launched the missiles that brought down a Ukraine International Airlines jet near the Iranian capital on Wednesday, killing all 176 people on board. The disaster unfolded amid escalating tensions with the United States over the killing of a revered Iranian commander, Maj. Gen. Qassim Suleimani.

For the first three days after the crash, Iran denied growing international accusations that it had shot the plane down, and looked as if it was engaged in a cover-up. The Iranian authorities insisted that the jetliner had gone down for mechanical reasons, and refused to cooperate with investigators. They also began to remove some evidence from the scene.

But then, as the uproar mounted, Iranian leaders admitted that they had shot the aircraft down, citing human error.

That admission limited the blowback from abroad — but threw a match on the volatile situation at home. Anti-government protests that had quieted when General Suleimani was killed in a drone strike in Iraq rekindled across the country.

Still, analysts argued that this latest wave of internal unrest could ultimately strengthen those in Iran who are pressing to confront the United States. Already, they were seeking to blame Washington for the protests.

On Sunday, the unrest spread outside Tehran, the capital, to at least a dozen cities. Security forces fired tear gas, rubber bullets and eventually live ammunition to disperse demonstrators in Tehran. By late Sunday night, several people had been wounded, witnesses said.

Unlike previous waves of opposition, some of the outrage this time has come from conservatives who ordinarily support the government, as well as from the usual critics.

Headlines in hard-line newspaper demanded resignations, and the commander-in-chief of the Revolutionary Guards, Gen. Hossein Salami, issued a very rare public apology. In a televised address, he all but begged Iranians to return to the nationalist zeal that only days earlier had seemed to fill the country, after General Suleimani’s killing.

Iran responded to his death by firing missiles at bases in Iraq where American forces were stationed. “We achieved a great victory,” General Salami said, though the missile barrage injured no one and did little serious damage. “But the crash of the airplane has tarnished it.”

He said he wished he, too, had “crashed and burned” on the jet.

The editor in chief of the Revolutionary Guard’s Tasnim news agency, Kian Abdollahi, said that attempts by government officials to lie about what had happened were as great a “catastrophe” as the crash itself.

“Officials who misled the media are guilty too,” he said on Twitter. “We are all ashamed before the people.”

Analysts say the uproar, however, is unlikely to dampen the Iranian appetite for confrontation with the West.

Iranian hard-liners habitually suspect that American covert operations are behind domestic protests, and the unvarnished pleasure the White House seemed to take in the events unfolding in Iran over the weekend may only harden that view, analysts said.

“We are following your protests closely and are inspired by your courage,” President Trump tweeted on Sunday.

Ali Vaez, Iran project director at the International Crisis Group, said that even as they took tough measures to suppress protests at home, Iranian leaders might lash out against Washington, covertly or otherwise.

“They believe that the U.S. and its allies in the region are fueling and exploiting internal discontent in Iran,” he said. “The game will return to Iran’s comfort zone: indirect attacks against the United States and its allies in ways that would allow plausible deniability and minimal risks of reprisal.”

Over the last year, the Trump administration has hit Iran with a so-called “maximum pressure campaign” of painful economic sanctions aimed at pressuring Tehran to submit to new restrictions on its military activities and nuclear program. Iranian officials describe it as economic warfare.

If hawks in Washington view the protests as evidence of success, that could work against Iranians who favor compromise with the United States — and strengthen hard-liners who favor confrontation, said Sanam Vakil, a scholar at Chatham House.

“Security-focused conservatives are thinking they can’t come to the table now because it would be weak,” she said.

General Salami of the Revolutionary Guards, in his apology and plea for unity on Sunday, appeared eager to rally Iranians once again against their perennial rival since the 1979 Islamic Revolution.

“We are at war with the United States,” he said. “We do not consider the conflict with the United States over. We are the soldiers of the people, and we will sacrifice ourselves for you.”

“Iran has risen,” he said, noting that its military had dared fire missiles toward American forces on bases in Iraq — even if it did so without much chance of damage or casualties. “Iran is proud and the whole world has seen our power.”

By acknowledging belatedly that Iran’s own military had brought down the jet, Iranian leaders avoided the prospect of greater international isolation. European and other governments that had sought to trade with Iran or mediate its dispute with Washington had all begun to cite evidence that Iranian forces shot down the plane.

Canada, the final destination of most passengers on the downed jet, lost 57 citizens. At a memorial event on Sunday at the University of Alberta in Edmonton, Prime Minister Justin Trudeau called the crash “truly a Canadian tragedy.”

“I want to assure all families and all Canadians: We will not rest until there are answers,” he said. “We will not rest until there is justice and accountability.”

In Tehran, the scale of the domestic backlash may have caught the government by surprise.

Uniformed members of the security forces and pro-government militia men were deployed in large numbers in cities around the country, apparently in an unsuccessful effort to discourage a second day of protests.

By the end of the night, at least several people had been shot in the back by security forces, according to witnesses and videos. Several protesters in Tehran said in interviews that a circle of militiamen had closed in and beaten them.

“The city is a security zone and special forces units are at every square,” Siamak Ghasemi, an economist living in Tehran, wrote on his Instagram page. The wrong group, he said, was being punished: “It’s as if civilians had brought down a military plane.”

Despite the heavy security presence, large crowds turned out. In many places, they chanted caustic slogans. Some denounced the country’s supreme leader, Ayatollah Ali Khamenei, which is a capital offense in Iran.

“The supreme leader is a murderer; his regime is obsolete,” demonstrators chanted in Azadi Square in Tehran.

“Our enemy is right here,” others chanted in a video circulating on social media. “They lie to us that it’s America.”

The protests in several cities were centered at universities and dominated by students, perhaps because many of those killed in the plane crash were recent graduates heading for further study in Canada.

“They killed our geniuses and replaced them with clerics,” young men and women chanted in the city of Shiraz.

Dozens of prominent film directors, artists and performers issued statements condemning the government’s handling of the crash and pulling their work from a prestigious competition.

“We are not citizens,” Iran’s best-known actress, Taraneh Alidoosti, wrote on her Instagram page; she has six million followers. “We are hostages, millions of hostages.”

A member of the Tehran city council issued a stinging statement of resignation: “Today we are faced with systematic lies, cover-ups and lack of accountability. In the current environment I have no hope for reform.”

And the only female Iranian athlete to win an Olympic medal also chose Sunday to announce that she had defected. “I am one of the millions of oppressed women in Iran who they have been playing with for years,” the athlete, Kimia Alizadeh, wrote on Instagram. She won a bronze medal in taekwondo in 2016.

Officials appeared to be scrambling to get behind the outpouring of public grief for those killed on the plane.

A billboard in downtown Tehran that had displayed a photo of General Suleimani was taken down. In its place was a black banner with the names of the victims and a verse about grief. In Tabriz and Tehran, some protesters could be seen tearing up photos of General Suleimani that had been hanging from poles.

Iranian media reported that local officials, prayer leaders and Revolutionary Guard commanders were visiting the families of victims to offer apologies and condolences.

Like the commander-in-chief of the Revolutionary Guards, though, Ayatollah Khamenei did his best to shift public attention back to the conflict with the Washington.

In a meeting with the visiting emir of Qatar, according to his website, he argued that the problems of the region were created by “the United States and its friends.”

Ian Austen contributed reporting from Ottawa.