Syria agreed in principle Friday to allow Arab observers into the country to oversee a peace plan, as pressure continued on President Bashar Assad to end the brutal crackdown on anti-regime protesters.

The acceptance came after a week in which the Arab League exerted heavy pressure on Syria, voting last week to suspend Syria from the 22-member organization and then giving Damascus three days to accept an observer mission or face economic sanctions.

The Arab League observer mission aims to prevent violence and monitor a ceasefire that Damascus agreed to last week in the league peace plan but has not implemented, The Associated Press reported.

A senior Syrian official said Friday that the government had agreed to the observer mission in principle but was “”still studying the details.” Nabil Elaraby, head of the Arab League, said in a statement Friday that he received “amendments” to the mission from Damascus, which the League is studying.

The original proposal by the Arab League had been for a 500-member observer mission, but AP reported that the number has dropped to 40. It was unclear, however, which party – the Arab League or Syria – had ordered the reduction

Meanwhile, the bloody crackdown continued on Friday, with activist groups reporting that security forces killed at least 16 anti-government protesters.

Violence has raged in Syria all week long, with more than 70 people killed on Tuesday alone, in what observers said was one of the bloodiest days of Assad’s eight-month crackdown on anti-regime protesters.

Meanwhile, the opposition is fighting back, and Syrian army defectors attacked an intelligence complex on the edge of Damascus early on Wednesday morning.

It was the first reported assault on a major security facility in the eight-month uprising against Assad.