Twenty people were killed in Syria Monday in a renewed crackdown by government forces on pro-democracy protesters, as Turkey intensified its verbal attack on Syrian President Bashar al-Assad, dpa reported.
Activists based in Beirut told dpa that the casualty toll increased to 20 in Monday's violence, most of whom were from the restive province of Homs.
Among those killed was a Saudi national visiting his sisters in Homs, activists said.
The latest violence also wounded two Turkish pilgrims, when their buses came under fire near Homs.
The two were injured when what they believed were Syrian soldiers attacked their bus, which was returning to Turkey via Syria from the Muslim hajj in Saudi Arabia.
The violence prompted Turkish Prime Minister Recep Tayyip Erdogan to warn al-Assad that his days are numbered.
Erdogan told a meeting in Istanbul that al-Assad could not stay in power indefinitely through the use of military power.
"No matter how hard you try to hold on to power with your tanks and your weapons, a day will come and you will go. Because no worldly authority has ever lasted forever," Erdogan said, according to the Turkish state news agency Anadolu.
The victims continued to ride the bus north until they crossed the Syrian-Turkish border at Cilvegozu, at least 130 kilometres from where the attack allegedly occurred.
Once in Turkey, both the driver and the wounded passenger were admitted to hospital.
Lebanon-based activist Omar Idlibi accused the Syrian security forces of carrying out the attack against the Turkish buses because of Turkey's policies against al-Assad's government.
The attack is likely to further deteriorate Turkey's relations with Syria, which have been strained since the government crackdown on pro-democracy protesters that began in mid-March.
More than 3,500 people have been killed in Syria since demonstrations started demanding the ouster of al-Assad, according to the United Nations.
The official Syrian Arab News Agency (SANA), meanwhile reported that authorities on Monday carried out an operation in the al-Bayada neighbourhood in Homs, killing "four terrorists" and confiscating a large amount of weapons.
"The weapons included assault rifles, explosives, pump-action shotguns, rocket-propelled grenades, sniper rifles, as well as Turkish and US-made handguns," it added.