"We urge the British Muslim communities to continue the generous and tireless efforts to support all of those affected by the crisis in Syria and unfolding events in Iraq, but to do so from the UK in a safe and responsible way," the open letter, released Friday, says.

An estimated 500 British Muslims are believed to have taken up arms in the foreign-charged war in Syria.

Security services say the influx of Westerners to Syria creates a threat to the West, when radicalized militants return home from fighting in the region.

Britain has stepped up security at airports after US officials said that they were concerned that Al-Qaeda operatives in Syria and Yemen were developing bombs that could be smuggled onto planes.

Western officials are worried that the recent battlefield successes of the so-called Islamic State in Iraq and Levant (ISIL), an Al-Qaeda splinter group, have drawn a growing number of militants from America and Europe to the cause and they would have easy access to flights headed for US cities.

"As we near the end of the first week of Ramadan our message is simple, we have come together to urge British Muslim communities not to fall prey to any form of sectarian divisions or social discord," said Qari Mohammad Asim, an Islamic prayer leader in the northern English city of Leeds.

Violence in Iraq escalated after the ISIL militants took control of Mosul, in a lightning advance on June 10, which was followed by the fall of Tikrit, located 140 kilometers (87 miles) northwest of the capital, Baghdad.

The ISIL has vowed to continue its raid towards the capital.

Soldiers of the Iraqi army have been engaged in heavy fighting with the militants in different fronts and have so far been able to push back militants in several areas.

Maliki has said Saudi Arabia and Qatar are responsible for the security crisis and growing terrorism in his country, denouncing the Al Saud regime as a major supporter of global terrorism.

SHI/SHI