While appearing to concede to outside pressure, Syria continued its crackdown on its people Saturday as troops stormed a central town and a northwestern region in search of opponents to the regime, killing at least 15 people, activists said.

The attacks on the town of Shezar in the central province of Hama and on the restive Jabal al-Zawiya region near the Turkish border came as pressure mounted on Damascus to end its eight-month crackdown on anti-government protesters. The UN estimates more than 3,500 people have been killed since the unrest began in mid-March.

The British-based Syrian Observatory for Human Rights and activist group, the Local Coordination Committees, said that land and cellular telephone lines and electricity were cut in the Jabal al-Zawiya region.

The LCC said that around half of the 15 people who died were killed in the northwest province of Idlib.

The Syrian Observatory had a higher death toll of 16, saying that two civilians and two army defectors were killed in a clash with troops in Qusair near the border with Lebanon, as well as four members of the air force intelligence whose car was ambushed in Hama.

The military actions came a day after the government agreed in principle to allow the Arab League to send in dozens of observers to oversee a peace plan that calls on the government to stop attacking demonstrators, pull tanks out of cities and begin negotiations with the opposition.

But even the threat of economic sanctions may not be enough to stop the violence in Syria, says one observer.

"There is very little else the Arab League can do," Reuters senior correspondent Khaled Oweis told CTV News Channel in an interview from Amman, Jordan.

Asked about the possibility of intervention by the international community, he replied, "No foreign power has the appetite to do that right now. … If this crackdown continues, we could see it but not immediately."

Speaking at the Halifax International Security Forum, Defence Minister Peter MacKay said the successful mission in Libya should not be used as a blueprint for potential interventions in Syria or Iran.

While there was a "moral obligation" to intervene in Libya, MacKay said such action in other countries could not be considered lightly because of the dangerous potential fallout.

"There's a danger in creating a scenario that says there is 'world police' that are going to start singling out countries and enforcing what those governments -- legitimate or not -- should be doing," MacKay said during a panel discussion Saturday.

"I am very loathe to say that you can take a template and apply it uniformly."

The Arab League, which has already suspended Syria's membership, gave Damascus three days on Wednesday to accept the observer mission or face economic sanctions.

The Arab League observer mission aims to prevent violence and monitor a cease-fire that Damascus agreed to last week but has been unwilling -- or unable -- to implement.

Nabil Elaraby, the head of the Arab League, said in a statement Friday that he received "amendments" to the monitoring mission from Damascus, which the league is studying. He gave no details on the changes Syria seeks.

The original league proposal had been for a 500-member observer mission but the number has dropped to 40, said Ibrahim el-Zaafarani, an Egyptian member of the Arab Medical Union who is expected to be part of the team for Syria.

Violence has escalated in Syria over the past week, as army dissidents who sided with the protests have grown more bold, fighting back against regime forces and even assaulting military bases. Activist groups said security forces on Friday killed at least 16 anti-government protesters.

With files from The Associated Press and The Canadian Press