Syrian security forces are pounding the port city of Latakia for a fourth straight day as part of the government's widening crackdown on dissent.

Activists and residents say at least five people were killed Tuesday in Latakia. They say security forces have killed at least 35 people in the city since Saturday.

A U.N. agency says as many as 10,000 Palestinians are missing after fleeing a refugee camp in Latakia. U.N. Relief and Works Agency Spokesman Christopher Gunness told VOA Tuesday the refugees fled the camp Monday under heavy gunfire and that the agency has “no idea” where they are.

An aide to Palestinian President Mahmoud Abbas said the Syrian attack on the camp amounts to a “crime against humanity.”

Syrian officials have given a different account of events in Latakia. They deny the city was shelled from the sea, and say that naval vessels were on routine duty to protect the coast and prevent arms smuggling.

Latakia and the central city of Homs are among the Syrian cities that have seen large protests demanding the resignation of President Bashar al-Assad.

On Monday, Syrian troops backed by tanks carried out raids and arrests in Houla, a town near Homs.

Meanwhile, Turkey has warned neighboring Syria that its military operations against civilians “must end immediately and unconditionally.”

Turkish Foreign Minister Ahmet Davutoglu said Monday this “is our final word to the Syrian authorities.”

The Turkish foreign minister visited President Assad in Damascus last week to urge an end to his brutal crackdown against the anti-government uprising. Mr. Davutoglu said Monday that unless the bloodshed ends immediately, there will be nothing left to discuss with Syrian authorities.

Rights groups and activists say at least 1,700 people have been killed since the start of the government's crackdown.