BEIRUT — Pressure mounted on Syrian President Bashar al-Assad on Sunday as Turkey evacuated nationals from its diplomatic missions and the Arab League scheduled a meeting in Morocco on Wednesday to explore further action against the Syrian government.

Among the measures that will be discussed are possible ways of providing protection for civilians in Syria, the Arab League’s secretary general, Nabil Elaraby, told reporters in Tripoli.

He said the league may turn to the U.N. Security Council for help, a step that would echo the push toward military intervention against Libya this year. It also suggested that Arab leaders are serious about implementing the decision to suspend Syria’s membership and seek ways to halt the violent crackdown against the country’s protest movement.

In a further setback for Damascus, Turkey said Foreign Minister Ahmet Davutoglu would meet with the Arab foreign ministers attending the gathering in Morocco, a sign that the region is closing ranks against Assad after he failed to implement an Arab League peace plan.

The surprise vote Saturday by 18 of the Arab League’s 22 member states to suspend Syria’s membership and open talks with the Syrian opposition about a post-Assad transition triggered a furious reaction in Damascus.

Tens of thousands of pro-government demonstrators turned out in the cities of Aleppo and Damascus on Sunday to stage angry demonstrations denouncing the Arab move, which opens the door to a broader escalation of international pressure on Assad.

The demonstrations followed overnight attacks by enraged, stone-throwing hordes of Assad supporters against the embassies of Saudi Arabia and Turkey.