Violence sweeping across Syria has killed 25 people, most of them in a battle between troops and a growing force of army defectors who have joined the movement to oust the autocratic president, activists say.
The Arab League, meanwhile, has agreed on the details of economic and diplomatic sanctions against the regime.
The revolt against Bashar Assad's rule began with peaceful protests in mid-March, triggering a brutal crackdown.
The unrest has steadily become bloodier as defectors and some civilians take up arms, prompting the United Nations' human rights chief to refer to it this week as a civil war and urge the international community to protect Syrian civilians.
Sanctions by the United States, the European Union, Turkey and the 22-member Arab League have so far failed to blunt the turmoil, but are leaving Mr Assad's regime increasingly isolated.
Arab League ministers meeting in the Gulf nation of Qatar to finalise the bloc's penalties agreed on a list of 19 Syrian officials subject to a travel ban.
Among them are Cabinet ministers, intelligence chiefs and security officers, but the list does not include Mr Assad.
Many of the Arab sanctions, which were first announced last Sunday, went into effect immediately, including cutting off transactions with the Syrian central bank, halting Arab government funding for projects in Syria and freezing government assets.
The Arab League also agreed to ban the supply of all weapons to Syria.
The worst violence took place in the restive north western city of Idlib.