BEIRUT — Arab League observers were due to arrive today in Syria in an attempt to ensure the government’s compliance with demands to end a nine-month crackdown on dissent, even as activists reported at least 10 deaths from intense shelling by government forces in the center of the country.

The opposition has warned that the government, which has been besieging the Baba Amr district in the city of Homs for days, was preparing for a massive assault on the area. Activists said today’s shelling using mortars and heavy machine gun fire was the most intense since Friday.

The British-based Syrian Observatory for Human Rights, which reported the latest deaths, called on Arab observers to head immediately to Homs to witness the violence.

Amateur videos posted by activists on the Internet showed gruesome footage of at least four corpses lying in pools of blood in front of a house in Baba Amr, where they reportedly died from mortar shells that struck the neighborhood.

Men could be heard crying for help and women wailing in the video, which also showed several destroyed homes and cars.

“We urge the Arab observers to head immediately to Baba Amr to be witnesses to the crimes against humanity that are being perpetrated by the Syrian regime,” the Observatory said in a statement.