Relations between Turkey and Syria continued to deteriorate Monday after gunmen in northern Syria opened fire on a convoy of buses carrying Turkish pilgrims back from the Hajj in Saudi Arabia.

Two Turkish citizens were wounded in the attack and were treated at a hospital near the border after the convoy crossed into Turkey. Turkish media said the buses were attacked after they asked for directions at a checkpoint and showed pictures of one bus with numerous bullet holes.

The latest incident came as Turkish Prime Minister Recep Tayyip Erdogan again condemned the Syrian government for the eight-month-long crackdown on opposition protests and warned President Bashar al-Assad that his days are numbered.

Mr. Erdogan said Syria's leaders can stay in power with tanks and cannons only up to a certain point and the day will come when they will also have to leave.

Last week, pro-government Syrian protesters attacked several Turkish diplomatic missions, resulting in the evacuations of diplomats and their families.

Also Monday, Russia's Foreign Ministry accused Western nations of undermining the chances for a peaceful resolution of the Syrian crisis by urging Mr. Assad's opponents not to seek compromise with the government. Foreign Minister Sergei Lavrov repeated Moscow's position that the Syrian opposition share responsibility for the violence and should face international pressure to enter talks.

British Foreign Secretary William Hague is scheduled to meet Monday with Syrian rebel leaders in London.

Meanwhile, the commander of a group of Syrian army defectors retracted earlier claims that his followers launched an unprecedented attack in Damascus.

A Turkey-based air force colonel who heads the Free Syrian Army, Riad al-Asaad, said in a video posted on the group's Facebook page Monday that Mr. Assad's government is attempting to tarnish the image of the revolution. But he did not attempt to clarify why his group had alternately claimed and disputed responsibility for Sunday's attack on a ruling Baath Party building in Damascus.

Syrian activists said several rocket-propelled grenades hit the building, and witnesses reported numerous explosions in the city center. There was no apparent damage or injuries.

The Arab League Sunday rejected a Syrian request to amend a plan that would end the country's deepening crisis. Syria's Foreign Minister Walid al-Moallem said the plan “compromised the country's sovereignty, but that Damascus had not rejected the mission.” The 22-member Arab League will meet again Thursday to discuss the Syrian crisis.

Damascus has been facing mounting international pressure to end the unrest. The United Nations says the crackdown has resulted in more than 3,500 deaths.