British Prime Minister David Cameron held talks with Russian President Vladimir Putin on Syria's civil war, a meeting which could set the tone for the G8 summit, with the West at odds with Moscow over the conflict.

The US will not rush to war in Syria as it did in the past in the region, White House chief of staff Denis McDonough said.

Rights activists have found torture devices and other evidence of abuse in government prisons in the first Syrian city to fall to the rebels, Human Rights Watch said in a report on Friday.

The US will not rush to war in Syria as it did in the past in that region, White House chief of staff Denis McDonough said on Sunday.

US President Barack Obama arrived in Northern Ireland on Monday for the first day of the G8 summit and potentially vexatious talks on Syria with his Russian counterpart Vladimir Putin.

Riot police fired water cannons and tear gas as they drove protesters out of Istanbul's Taksim Square and neighboring Gezi Park on Saturday, an intervention that came shortly after the Prime Minister warned that security forces "know how to clear" the area.

The Syrian news agency, citing initial reports, early on Sunday said that Israeli missiles struck a military research center near the capital Damascus.

In its effort to get rid of Assad regime the Obama Administration is preparing to supply lethal weapons to the Syrian opposition, a media report said on Tuesday.

After months of sharp differences, Russia and the United States have agreed to push both sides in Syria to find an end to the bloodshed, offering to hold an international conference in search of peace.

NATO Secretary General Anders Fogh Rasmussen on Friday welcomed a ‘clear’ US statement accusing the Syrian regime of using chemical weapons and said Damascus must let the UN investigate the allegations.