Arab foreign ministers and Turkey agreed a list of sweeping sanctions yesterday designed to cripple the Syrian regime of President Bashar al-Assad who has defied pressure to halt a bloody crackdown on protests.

As another 15 civilians were reported dead in Syria, the 22-member Arab League announced an immediate ban on transactions with the Syrian government and central bank and a freeze on Syrian government assets in Arab countries.

Further measures including a ban on Syrian officials visiting any Arab country and the suspension of flights are to be implemented at a date fixed at a meeting next week.

The sanctions, announced by Qatari Prime Minister Sheikh Hamad bin Jassim al-Thani after a meeting in Cairo, are the first time the organisation has imposed such harsh economic measures against another country in the region.

“We hope that (the Syrian regime) puts an end to the massacres so that this resolution (authorising sanctions) is not put into force,” said Sheikh Hamad, but he added that “the signs are not positive.”

He also called for “an end to the massacres, the freeing of prisoners and the withdrawal of tanks” from Syrian cities.

The violence showed no sign of abating yesterday, with Syrian security forces accused of killing at least 15 civilians, six of them in the flashpoint region of Homs that has been under siege for several weeks.Syrian state TV said in a terse statement that the decision to impose sanctions on a member state was “an unprecedented measure” while several hundred Syrians gathered in a central Damascus square to denounce the move.

Long seen as a weak institution dominated by the region’s autocrats, the Arab League has taken on an increasingly activist role during the pro-democracy Arab Spring demonstrations of the past 12 months.

Nineteen Arab League members voted for the Syrian sanctions, however Iraq abstained from the vote and said it would refuse to implement the sanctions, while Lebanon completely “disassociated itself,” Sheikh Hamad said. Syria is a suspended member.