BEIRUT — Army shellings and shootings raged in at least three insurgency hot spots across Syria

BEIRUT —

Army shellings and shootings raged in at least three insurgency hot spots across Syria on Tuesday, including what anti-government activists described as the deadly bombardment of a cemetery in a Damascus suburb during funerals for victims of a freshly discovered massacre.

The new violence was reported as Syria, backed by Russia, its most important foreign supporter, rejected warnings by President Barack Obama about possible intervention in the 18-month-old conflict if Syria were to move or deploy unconventional weapons.

Speaking to reporters in Washington on Monday, Obama said the United States regarded the movement or utilization of such weapons to be “a red line.” U.S. intelligence officials believe the Syrian government has a large quantity of chemical weapons. It is not known whether the Syrians have biological weapons.

After meeting Tuesday with a Syrian deputy prime minister, Jamil Qadri, in Moscow, the Russian foreign minister, Sergey Lavrov, reiterated the Kremlin's longstanding opposition to foreign intervention and repeated Russia's desire to help the Syrian government and the rebels reach their own settlement. Qadri, appearing with Lavrov at a news conference at the Russian Foreign Ministry, said

Obama's warning about unconventional weapons was a pretext to justify interference. “The West is looking for an excuse to intervene directly in the affairs of our country,” Qadri said, adding a jab about claims by the Bush administration of weapons of mass destruction in Iraq, used to justify the U.S. invasion of that country in 2003, that were never found.

While fighting continued around Aleppo and Damascus, Syria's largest cities, activists said the most serious violence appeared to be the shelling of a Damascus-area cemetery named Modamiyah, where large crowds had gathered to bury at least some of the 40 bodies found in the basement of a mosque following a raid by a newly formed militia of Alawites, the ruling minority sect of President Bashar Assad. “We knew we would find a massacre after they left,” said Ahmad, an activist in the area. It was unclear how many of the funeral mourners were killed. But the victims found in the mosque marked the third instance in the past week of a mass killing following raids by government troops or their supporters, fueling speculation that the Assad government has begun a new campaign of extrajudicial killings to weaken the opposition's support among civilians.

The Local Coordination Committees, an anti-Assad activist group, said at least 152 people had been killed on Tuesday around the country. That tally, which could not be independently corroborated, included 93 in Damascus and its suburbs, mostly in the Modamiyah cemetery.