Syrian security forces are using heavy machine gun fire in the port city of Latakia, where a President Bashar al-Assad's government has been cracking down on opposition demonstrators the past four days.

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.”

Latakia and the central city of Homs are among the Syrian cities that have seen large protests demanding Mr. Assad's resignation.

In a separate development, Syria said Tuesday it has begun withdrawing its forces from Deir el-Zour, about a week after launching attacks on the eastern town. The state-run SANA news agency says law enforcement officers are removing barriers that were set up by “armed terrorist groups.” It also says a number of “gunmen” have been arrested.

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.