Turkish Foreign Minister Ahmet Davutoglu is going to Syria to demand an end to a crackdown on protests by President Bashar al-Assad’s government.
Turkish PM Recep Tayyip Erdogan earlier said he was running out of patience over «the savagery» of Syria’s security forces towards the protesters.
Mr Davutoglu’s visit comes as Saudi Arabia, Kuwait and Bahrain have all recalled their ambassadors to Damascus.
Syrian tanks again pounded the eastern city of Deir al-Zour on Monday.
At least 50 people died on Sunday after the army launched a pre-dawn assault.
Activists said that as in recent days, many people had been afraid to leave their homes or take injured people to hospital for fear of being attacked.
Syrian state TV has reported that Mr Assad has appointed a new minister of defence, former army chief of staff Gen Dawoud Rajha. He replaces Gen Ali Habib, said the report.
Sana has also said troops are withdrawing from the city of Hama, which has come under heavy attack in recent days – witnesses say scores of people have died there.
Access to Syria has been severely restricted for international journalists and it is rarely possible to verify accounts by witnesses and activists.
Human rights activists say at least 1,700 civilians have been killed and tens of thousands arrested since the uprising began in mid-March. More than 300 people are believed to have died in the past week alone.
Source: bbc.co.uk