Turkish Prime Minister Recep Tayyip Erdogan telephoned Syrian President Bashar al-Assad Tuesday and urged him to stop a bloody crackdown on protesters and launch reforms, Anatolia news agency reported.

Erdogan told the Syrian leader to "refrain from violence and end the unrest" that has swept Syria since anti-regime protests erupted in March, the report said.

Around 4,300 Syrians who fled a brutal crackdown against pro-democracy protesters are staying in camps in southern Turkey, the Anatolie news agency reported Saturday.

Hundreds have fled in the last 24 hours, the agency said citing local sources.

The White House significantly toughened its stance on Syria on Friday, calling for an "immediate end to brutality and violence" and warning President Bashar Assad was leading his nation on a "dangerous path."

White House spokesman Jay Carney issued a statement after Syrian forces killed at least 25 people in nationwide democracy protests and as security forces launched a long-feared crackdown on the northwestern flashpoint town of Jisr al-Shughur.

Turkey has offered Moammar Gadhafi guarantees to leave Libya but has yet to receive a reply, as rebels say loyalist forces killed 20 people in a fierce assault on Misrata.

Fresh NATO-led strikes sent up plumes of smoke Friday in Tripoli, where the strongman has his residence and headquarters.

Turkish Prime Minister Recep Tayyip Erdogan accused the Syrian regime of perpetrating an "atrocity" against anti-government demonstrators, the Anatolia news agency reported Friday.

"I talked to Mr. Assad (Syrian President Bashar al-Assad) four or five days ago. ... But they underestimate the situation," Erdogan told Anatolia.

About 1,000 more Syrians have fled to Turkey, bringing to some 1,600 the number of people taking refuge in the country amid unrest in their homeland, a government official said on Thursday.

"According to information from local authorities, about 1,000 more people have arrived and the total is now around 1,600," the official, who declined to be named, told Agence France Presse.

Turkey will not close its doors to refugees fleeing the repression in Syria, Prime Minister Recep Tayyip Erdogan said on Wednesday as he expressed his sadness about unrest across the border.

Erdogan, who has become increasingly critical of the President Bashar Assad's regime, also urged authorities in Damascus to demonstrate more tolerance towards its civilians.

Turkish Prime Minister Recep Tayyip Erdogan called Syrian leader Bashar Assad Friday in another effort to press for reform to end deadly unrest in the Arab country, a government official said.

Erdogan "emphasized again the importance of reform," the official told Agence France Presse on condition of anonymity, refusing to give other details.

Britain summoned Syria’s ambassador Friday in coordination with other EU nations to warn of fresh sanctions against the regime if it fails to stop a crackdown on protesters, as Turkey's premier said it was premature to say whether President Bashar al-Assad should quit.

In a statement, the Foreign Office said it had "called in the Syrian Ambassador Dr. Sami Khiyami ... to express the UK’s strong concerns about the ongoing situation in Syria."

Turkey on Tuesday urged Moammar Gadhafi to "immediately" cede power and leave Libya, in its first public call on the veteran strongman to go.

"We wish that the Libyan leader pulls out from Libya and cedes power immediately -- for himself and for the future of his country -- without causing more bloodshed, tears and destruction," Prime Minister Recep Tayyip Erdogan told reporters.