The ruler of the Gulf state of Qatar has said Arab countries should send troops into Syria to stop government forces killing civilians there.
Sheikh Hamad bin Khalifa Al Thani told US news channel CBS "some troops should go to stop the killing".
It is the first time an Arab leader has publicly called for military intervention in Syria.
More than 5,000 civilians have been killed since anti-government protests erupted in Syria in March, the UN says.
Qatar was the first Arab country to join the Nato-led operation in Libya, which led to the downfall of Libyan leader Col Muammar Gaddafi.
It has also led regional criticism of the crackdowns on protesters by President Bashar al-Assad in Syria and in Yemen by President Ali Abdullah Saleh.
Asked if he was in favour of Arab nations intervening in Syria, Sheikh Hamad said: "For such a situation to stop the killing... some troops should go to stop the killing."
The Arab League has despatched 165 observers to Syria to monitor compliance with a peace plan, but members have expressed doubts as to the mission's efficacy.
More than 400 civilians have been killed in Syria since the observers began their mission in December, according to the UN.
In Syria, troops backed by tanks are continuing an assault, begun on Friday, on the rebellious mountain town of Zabadani, near the Lebanese border, witnesses say.
Reuters news agency quoted an exiled opposition leader as saying 40 people in the town were injured in the fighting on Saturday.
Casualty reports are hard to verify because most foreign media are barred from reporting freely in Syria.