Syrian forces scrambled Saturday to destroy evidence of last week's bloody crackdown in Latakia that killed dozens and sent Palestinian refugees fleeing, activists said as UN investigators arrived in Damascus.

Security forces were seen scrubbing blood off the streets and walls of al-Ramel refugee camp ahead of the cross-agency mission’s anticipated arrival in the port city.

The delegation was dispatched from Geneva in response to a damning report to the Security Council on Syrian leader Bashar Assad's "apparent shoot-to-kill" policy.

That report had urged an end to excessive use of force against demonstrators and the killing of protestors, torture and ill-treatment of detainees and enforced disappearances.

A European diplomat says the last-minute cleanup in Latakia confirms existing suspicions and appears timed to coincide with the arrival of UN officials.

It fits "perfectly with the version of events which the regime is denying: that there was an attack on Latakia camp, home to thousands of UN registered Palestinian refugees who were forced to flee as they came under fire," the diplomat said.

More than 60 civilians, mostly Palestinians, have died in Latakia since forces launched an offensive last Sunday, activists say. Thousands fled as gunboats were used in the first attack from the sea since the start of a pro-democracy revolt in March, according to activists.

At least 2,000 civilians have died since the unrest began, rights activists say.

Security forces said their campaign targeted "armed men" who "opened fire on residents" in Latakia, but witnesses said the assault began after a small group held a peaceful demonstration.

On Saturday, regime officials brought television crews to one section of Latakia which had been opened to inspection, rights activists told Ma'an.

Prior to filming, security forces scrubbed off dried, days-old blood from the streets and planted flowers in a bid to present the area as a regular public space.

Assad's "killing machine can wash the blood off the streets but not off its hands," said the diplomat, who spoke on the condition of anonymity out of concern for colleagues in Syria.

"The evidence ... is overwhelming and undeniable," he said.

Badil, a Palestinian refugee rights group in the West Bank, called Sunday for “full transparency and accountability for recent events in Latakia camp, in accordance with international law."

"There must be a credible and independent investigation, in line with international standards, into allegations that crimes against humanity have been committed," Badil said echoing remarks by frustrated diplomats.

But the UN's delegation is not authorized to investigate allegations of war crimes and other serious abuses.

Its mandate is to evaluate humanitarian conditions and draw up plans for resuming public services in the coastal town and six more of the hardest-hit areas across Syria.

On Sunday, exiled Syrian dissident Radwan Ziadeh urged a UN panel to recommend that the Security Council refer the situation in Syria to the prosecutor of the International Criminal Court.

"Leadership and impartiality must be strongly demonstrated with regards to Syria as it was in the case of Libya," said Ziadeh, who has criticized the international community's failure to act.

He proposed an independent commission to hold investigations "into the crimes committed by the Syrian government in recent months."

In Latakia, meanwhile, UN officials say about 7,500 residents of the refugee camp have not returned due to fears of new attacks. The UN refugee agency has tracked down 6,000 Palestinians who fled.

Many of those who remain missing have been locked into a sprawling stadium complex known as Latakia Sports City, activists say. As many as 4,000 people, mostly Palestinians, are believed to be held there.

Syrian rights advocate Ammar Abdulhamid says he is waiting to see if the prisoners will be moved from the stadium when the UN delegation arrives "because, right now, it is still full."