Syria’s government threatened Saturday to take firmer measures to rein in protests challenging President Bashar al-Assad’s rule, even as new clashes broke out during funeral services for some of those killed in demonstrations Friday.

Human rights groups and residents said that at least 37 people have been killed in Syria since the latest round of violence began with protests after midday prayers Friday in several cities, including Damascus, Daraa, Homs, Harasta, Latakia, Baniyas and Tartous.

“We are dying,” said Razon Zaitonah, a human rights lawyer in hiding in Damascus, the capital.

Citing reports from contacts across the country whom she had reached by phone, Zaitonah said security forces had fired on marchers attending funerals of slain demonstrators in Homs and in Daraa, the southwestern city where Syria’s almost month-long uprising began.

Ammar Qurabi, chairman of the National Organization for Human Rights in Syria, said security forces used tear gas and bullets to break up demonstrations at funerals in Daraa. Qurabi also reported bloodshed in Latakia, where he said authorities opened fire on protesters who had tried to stay in the streets overnight Friday. But he said he had only sketchy reports of the number of casualties in those places because of communication problems, especially around Daraa. All Internet connections to Daraa had been severed, activists said, permitting them to communicate only by cellphone.

Muntaha al-Atrash, 70, of Damascus, said her relatives in Harasta, outside the capital, told her that two people had been killed Friday and 12 injured in clashes with security forces there. She said she had been told that police were also plucking wounded demonstrators from hospitals and detaining them.

Atrash said contacts in Daraa had told her that injured victims there had been killed “in cold blood” by security forces. “Even the Israelis didn’t do that in our wars,” she said.

Atrash, who said her father was Sultan al-Atrash, the leader of the Syrian revolt against France in 1925, praised the demonstrations and predicted that Assad would go, like other authoritarian leaders in the region.

“It’s a matter of time,” she said.

Pro-democracy activists also urged Syrians to stage continuous demonstrations in the buildup to mass protests Friday on the Muslim day of rest, Qurabi said.

In a stern statement issued Saturday, the Interior Ministry suggested that authorities are prepared to crack down harder on the protests challenging the Assad dynasty’s four-decade-long grip on the country.

The statement, carried by the state-run Syrian Arab News Agency, said there was “no more room for leniency or tolerance” toward disorder.

But the ministry’s statement also sounded a note of frustration that previous gestures by the government had failed to pacify opponents. In recent days, Assad has dissolved the cabinet, repealed laws denying citizenship to ethnic Kurds and promised to ease restrictions on civil liberties.

The ministry blamed the continuing unrest on unidentified foreign plotters, outside satellite news channels and “spiteful individuals.”

President Obama issued a statement Friday condemning the violence and calling on the Assad government to heed Syrians’ demands for a more responsive and open government. The European Union’s foreign policy chief, Catherine Ashton, also condemned the violence and urged the government to respond to calls for reform.

Qurabi said Saturday that his group has estimated that about 200 people have been killed since the revolt began.

In unrest elsewhere, government forces in Yemen fired bullets and tear gas at demonstrators in the capital, Sanaa, and the southern city of Taiz as President Ali Abdullah Saleh resisted a diplomatic push for his resignation, the Associated Press reported. In Sanaa, 11 people were said to be injured by gunfire and dozens of others by tear gas or the crush of crowds. Three people suffered serious gunshot wounds in Taiz, the AP said.

Tabei is a special correspondent. Special correspondent Muhammad Mansour contributed to this report.