BEIRUT, Lebanon - Syria's top opposition leader called on the Arab League to bring the United Nations into the effort to stop the regime's bloody crackdown on dissent as security forces pressed ahead with raids and arrests and killed at least seven more people.

Burhan Ghalioun, the Paris-based leader of the Syrian National Council, made the plea Sunday as Arab League officials were setting up teams of foreign monitors as part of their plan aimed at ending nine months of turmoil that the United Nations says has killed more than 5,000 people.

Opposition groups say the Arab League is not strong enough to resolve the crisis, which has escalated beyond mass demonstrations into armed clashes between military defectors and security forces and a double suicide bombing that shook Damascus on Friday.

In a televised speech marking Christmas, Ghalioun called on the league "to ask the Security Council to adopt its plan in order to increase possibilities of its success and avoid giving the regime an opportunity not to carry out its obligations."

The opposition council "holds the international community to its responsibilities," he said. "The barbaric massacre must stop now."

The league has begun sending observers into Syria to monitor compliance with its plan to end the crackdown on political opponents. President Bashar al-Assad agreed to the league plan only after it warned that it could turn to the Security Council to help stop the violence.

The plan requires Assad's government to remove its security forces and heavy weapons from city streets, start talks with opposition leaders, and allow human rights workers and journalists into Syria.

The opposition has accused Assad of agreeing to the plan only to buy time and forestall more international sanctions and condemnation.

Mohamed Ahmed Mustafa al-Dabi, head of the observer team, traveled to Damascus late Saturday after meeting with league chief Nabil Elaraby to discuss mission arrangements. More monitors are expected to arrive Monday.

On Sunday, the British-based Syrian Observatory for Human Rights and the Local Coordination Committees activist groups said that troops shelled the town of Juraithi in the eastern province of Deir el-Zour, killing one person. They said security forces killed three others in the village of Kouriyeh, also in Deir el-Zour.

The groups also reported that parts of the restive central city of Homs were bombed Saturday, killing at least three people and wounding dozens.