Syria’s military moved into the Mediterranean port of Baniyas early Monday, human rights workers and activists said, a day after at least 13 people — four demonstrators and nine members of the state’s security forces — were killed in violent clashes there.

Other activists said the unrest in Syria had reached Damascus University, Syria’s oldest and most prestigious institution of higher learning, in the nation’s capital. The Associated Press said there were reports that one student was killed, but the news service could not independently confirm the death.

Opponents of the Assad family’s dynasty said Monday that their numbers appear to be increasing.

“We are like a snowball that’s getting bigger every day,” said Haitham al-Maleh, a longtime opposition lawyer in Damascus who was recently released from prison.

The nearly month-long wave of protests has claimed an estimated 170 lives and presented the fiercest challenge to President Bashar al-Assad and his ruling Baath Party since he took over after the death of his father 11 years ago.

Thousands on both sides of the escalating conflict attended the Monday funeral services for those who were killed Sunday, said Nadim Houry, senior researcher in Human Rights Watch’s Middle East and North Africa division. He also said his organization and even activists in Syria have had difficulty determining the death toll from Sunday’s violence.

Al-Maleh said four protesters died in Baniyas on Sunday, a figure also reported by the Associated Press.

Syria’s official news agency, SANA, reported Monday that nine members of the armed forces, including two officers, had been killed near Baniyas on Sunday in a clash on the highway to Latakia.

The agency said an additional 32 people, including four civilians, had been injured, including an ambulance driver and an undetermined number of emergency medical technicians, when their vehicle came under fire.

The Syrian government has expelled many media organizations, and frequent outages of Internet and mobile phone service have hampered efforts by human rights workers and others to follow events inside the tightly regulated country.

Houry said those difficulties seemed even larger Monday. “It’s been hard to get a clear picture,” he said.

The Syrian government has blamed the killings on “armed groups” that ambushed the military convoy outside the city, a seaport that human rights activists said had been cut off by security forces Sunday.

The Washington Post was unable to independently verify accounts of what happened in Baniyas, but videos smuggled out of the country and played on Facebook and al-Jazeera have shown scenes from Daraa and other cities that show torched cars and demonstrators burning images of Assad and snatching up tear gas canisters and throwing them back at security forces. Others depict graphic violence, including people spraying gunfire from car windows and a group of what appear to be security forces beating a man with clubs and dragging away a body.

The violence has fed on itself, as protests lead to deadly clashes that create new demonstrations and calls for revenge during victims’ funerals. Activists have called for continuous demonstrations every day that would climax Friday, the Muslim prayer day.

The president has promised reforms, including revising the emergency decree in place since 1963, shaken up his government and repealed a measure banning citizenship to ethnic Kurds, but he has been unable to restore order.

“I see more violence,” Lamis K. Andoni, a political commentator, said in an appearance on al-Jazeera.

She said that although Assad continues to have support among many people who fear that the country could descend into chaos, there are signs that such support has begun to weaken.

Andoni said Kurds have continued to mount independent anti-government protests despite the shift toward granting them citizenship.

Tammam al-Barazi, an exiled Syrian journalist who writes for al-Watan al-Arabi, said the unrest has spread to Damascus University, where he said perhaps 1,500 students conducted a sit-in Monday.

Barazi’s contacts in Syria told him that armed pro-government thugs in civilian clothes — known as “shabiha” in Arabic — had moved to surround the campus.

SANA described a disturbance at the university on Sunday, saying that passersby had intervened to stop a person who had attacked women and tried to remove their head scarves.

“This is the first time something in Damascus is happening,” Barazi said.

Razan Zaitouneh, a human rights lawyer who is in hiding, said she could not confirm reports of a student’s death or other fatalities connected to protests Monday. But she said Syria’s security apparatus had been carrying out a campaign of mass arrests of activists, intellectuals and political leaders in the past two days. Among those detained were Fayez Sara, a well-known journalist and writer who had previously been imprisoned as a signatory of the Damascus Declaration for Democratic National Change, and George Sabra, a political figure in Syria.

Barazi said opponents of Assad’s rule are watching now to see whether the protest movement spreads into Damascus or Aleppo, the country’s third-largest city; those areas are strongholds of the Alawite minority that rules Syria’s mostly Sunni population.

“It’s still happening and it’s still spreading,” Barazi said.

The latest wave of anti-government demonstrations began after the arrest in March of a group of young Syrians in Daraa for writing anti-government graffiti.

Special correspondent Muhammad Mansour contributed to this report