Fierce clashes between government troops and opposition forces in Syria's western Latakia province are further dimming hopes that diplomats can salvage a cease-fire and end the bloodshed.

The London-based Syrian Observatory for Human Rights said the latest battles broke out Tuesday in the city of Haffeh and surrounding villages, where rebel forces had taken over several police stations.

The Observatory's Rami Abdurrahman said at least 15 government soldiers and three rebel fighters were killed in what he described as the heaviest clashes in the Latakia region since the start of the 15-month-long conflict.

In Jeddah, Saudi Arabia's foreign minister said prospects for ending the violence looked bleak. Prince Saud al-Faisal said Gulf Arab states have “begun to lose hope” that a cease-fire proposed by international envoy Kofi Annan could help.

The rebel Free Syrian Army said Monday it is no longer bound by an April cease-fire agreement, due to the government's tactics. Some military analysts warn the conflict has already passed the “point of no return.”

Meanwhile, Syria agreed to allow the U.N. and international agencies to expand humanitarian operations in battered areas of the country, a senior U.N. aid official said.

Syria also announced Tuesday it is expelling diplomats of several nations in response to their recent expulsions of Syrian diplomats.

The Syrian government said its retaliatory order includes the ambassadors and other staff of the United States, Britain, France and Turkey. Some of those diplomats already had been withdrawn from Syria in protest at the government's crackdown on the uprising.

State Department spokesman Mark Toner said the move against U.S. ambassador Robert Ford was an “empty gesture,” since Ford was recalled several months ago and is already in Washington. The spokesman said Ford will “continue to maintain contact with the Syrian opposition.”

Russian President Vladimir Putin arrived in Beijing Tuesday to meet with his Chinese counterpart, Hu Jintao. China has remained united with Russia in opposing any foreign intervention in the Syrian conflict.

U.S. Secretary of State Hillary Clinton meets with allies in Turkey Wednesday to discuss how best to pursue a political transition to end Syrian President Bashar al-Assad's rule.

Analyst Dan Goure tells VOA that Syrian government forces and the opposition are locked in a protracted fight.

“We are seeing the beginnings, maybe even the second phase, of a full-blown rebellion or even civil war in Syria.”

Goure is vice president of the Lexington Institute, an advocacy group in Arlington, Virginia, that says its mission includes “promoting America's ability to project power around the globe.”

The Syrian state news agency confirmed Tuesday that rebels have killed more than 80 security personnel, including a brigadier general, in recent days – the same period in which the Syrian Observatory for Human Rights has reported intensified rebel attacks on government checkpoints.

Goure says the most recent fighting shows the situation on the ground has changed, with far-reaching implications.

“Clearly the rebels are getting more capable and they're receiving support – weapons, possibly even training, from outside sources. And most importantly, after a year of efforts, the Syrian military … has been unable to suppress this. So this doesn't look good for Assad's government. All the trend lines are in the wrong direction.”

Speaking in Istanbul Tuesday, Turkish Prime Minister Recep Tayyip Erdogan reiterated that his country has no intention of intevening inside Syria, despite his fear that “the fire raging within Syria will engulf the whole region.”

The chairman of the U.N. Syria Humanitarian Forum, John Ging, saw a sign of hope in the agreement to allow more aid into Syria as a sign of hope. He told reporters in Geneva the deal represents “a step of progress”:

“Whether this is a breakthrough or not will be evident in the coming days and weeks, and it will be measured not in rhetoric, not in agreements, but in action on the ground.”

International mediator Kofi Annan is due to brief the U.N. Security Council on the Syrian conflict on Thursday, and will discuss the issue with U.S. Secretary of State Clinton in Washington on Friday.