Syrian forces killed three people on Monday a day after gunboats pounded Latakia, forcing thousands of Palestinians to flee a refugee camp in the port city, activists and a UN agency said.

The Palestinians condemned Syria over the violence as the UN Relief and Works Agency reported that more than 5,000 refugees had fled Ramel camp in southern Latakia under fire and demanded immediate access to the site.

Palestine Liberation Organization secretary general Yasser Abed Rabbo denounced the attack on the Ramel camp and said such violence was "part of the crimes against humanity" targeting Palestinians and Syrians alike.

Jordan, adding its voice to a recent chorus of Arab condemnation of the Syrian crackdown on dissent, urged Damascus to "immediately" stop the violence and "listen to reason," state-run Petra news agency reported.

But as the uprising turned five months old, the violence continued unabated.

Troops and tanks clamped down on Monday on the flashpoint province of Homs, targeting the provincial town of Hula where snipers shot dead an elderly man, the Syrian Observatory for Human Rights reported.

The Britain-based group said two other people were killed as they tried to escape from Latakia's Ramel district.

"The community of Hula is under siege... The army is carrying out raids and arrests under the cover of heavy gunfire," the rights group said.

"Security agents encircled all the entrances to Hula and they started shooting to terrify local residents. Then the army went in to make raids and arrests," it said.

Another rights monitoring group said "a large number of tanks entered Hula this morning" (Monday).

The operation came a day after gunboats joined the pounding of Latakia that killed as many as 26 people, in the first attack from the sea since Syria's anti-regime revolt erupted on March 15, activists said.

Many residents were allowed to flee the worst-hit districts of Latakia at dawn, but soldiers opened fire at a checkpoint, killing a man, and a woman also died when her car was hit as she tried to leave Ramel, the Observatory said.

At least six people were wounded.

One Latakia resident, declining to be identified, told AFP: "The shooting is coming from security forces on rooftops. They open fire for no reason -- we can't hear any other side shooting back at them."

A spokesman for UNWRA, which helps Palestinian refugees, said "thousands of the refugees have fled the camp" in Ramel.

"Between five and 10,000 people have fled," Chris Gunness said. "We need to get in there and find out what the hell is going on."

The PLO's Abed Rabbo later told AFP: "We strongly condemn the operations of the Syrian forces in raiding and shelling the Palestinian Ramel Camp in Latakia and the displacement of the population.

The attack on Ramel is considered "to be part of the crimes against humanity that have been directed at the Palestinian people and their Syrian brothers who are also the victims of this ongoing bloody campaign," he said.

Meanwhile Jordanian Prime Minister Maaruf Bakhit telephoned his Syrian counterpart Adel Safar to urge an end to military operations, saying "Syria should listen to reason and start implementing reforms."

He told him "military operations must stop to preserve Syria's unity and reforms should start to create a better future for the Syrian people," Petra news agency reported.

"World anger and rejection of the bloodshed in Syria are growing."

Syria has repeatedly said it is battling "armed gangs," and on Monday the state-run news agency SANA denied that naval vessels had attacked Latakia.

"Law enforcement members are pursuing armed men who are using machine guns, grenades and bombs in Ramel from rooftops and from behind barricades," it said.

SANA announced on Monday that President Bashar Al-Assad appointed a new governor for Aleppo province in northern Syria. He had already replaced the governors of Homs and Hama in central Syria and Daraa in the south.

The Syrian Observatory had said the naval vessels opened up on Latakia with heavy machine guns, and rights groups on Monday said 26 people were killed there, including two Palestinian men in Ramel.

On Sunday UNRWA's Gunness said reports from Ramel spoke of "fire from tanks which have encircled the area as well as fire from ships at sea."

Meanwhile Spain's El Pais newspaper reported that Madrid sent a special envoy to Damascus last month to convince Assad to accept a plan to go into exile. Madrid was "ready to offer asylum to Assad and his family in Spain," it reported.

The violence has killed around 2,200 people, including some 400 members of the security forces, according to rights activists.

The Local Coordination Committees, an umbrella group of activists, meanwhile reported that 260 people, including women and children, have been killed since the start of Ramadan on August 1.

A statement by the group said it was able to confirm that since the holy fasting month started there have been "260 martyrs... among them 14 women and 31 children. Two children were two years old."

But it warned that the number of deaths was "way higher" as many victims were still not identified.

The UN Security Council is due to hold a special meeting on Thursday to discuss human rights and the humanitarian emergency in Syria.

And Human Rights Watch said it had sent a message to Arab League chief Nabil Al-Arabi urging him to convene an "emergency meeting on Syria."