Manama/Tehran, Feb 20 (IANS) A Briton who is an advisor to Bahrain's King Hamad bin Isa al-Khalifa has been blamed for the violent crackdown on thousands of pro-democracy protesters in Manama's Pearl Square, a media report said Sunday.

Ian Henderson had earlier served as the head of Bahrain's state security for thirty years until 1998, Iran's Press TV reported.

The government has violently suppressed demonstrators who are demanding an end to the monarchy. The crackdown has left six people dead and hundreds of others wounded.

Bahraini protesters, who have been inspired by successful anti-regime uprisings in Tunisia and Egypt, were initially calling for democratic reforms but have now upped that call to nothing less than a regime change.

Tension is running high in the streets of Bahrain's capital, Manama. Despite the crackdown, anti-government protesters have taken to Pearl Square, the focal point of protests.

The developments come shortly after the army withdrew from the area after Crown Prince Sheikh Salman bin Hamad al-Khalifa ordered military vehicles to withdraw.

Shortly afterwards, protesters stormed the square and erected tents. Police fired teargas to disperse them.

On Saturday, the Bahraini king called for a national dialogue, but the offer was rejected by the main opposition bloc, Al-Wefaq, which says the government must first resign.

Four people were killed early Thursday when police cracked down on sleeping protesters in Manama.

Bahrain's most senior Shia cleric, Sheikh Issa Qassem, has described attacks on protesters as a "massacre" and said the government had shut the door to dialogue.

Western countries have urged Bahrain to show restraint in dealing with protesters and called for meaningful reform in the small Gulf state kingdom.

US President Barack Obama Friday phoned King Hamad bin Isa Al-Khalifa to urge restraint.

Bahrain, a close American ally, must respect the "universal rights" of its people and embrace "meaningful reform", he said.

Bahrain, a tiny country with a population of less than one million, is home to the US Navy's 5th Fleet and is near another key US ally in the region, Saudi Arabia.