DOHA, Qatar – Qatari authorities on Sunday blamed an Egyptian national for the suicide car bombing of a theater that killed one Briton and injured 12 other people in a rare attack in the tiny Gulf state.

The car bombing came days after a man purporting to be Al Qaeda’s leader in the Gulf called for attacks on Western interests. It also occurred on the second anniversary of the American led invasion of Iraq, but it was not clear if the two events were linked.

Qatari authorities identified a charred body at the site as the suicide bomber, Omar Ahmed Abdullah Ali. They said the Egyptian owned the car used in Saturday’s attack on the Doha Players Theater in the northern suburb of Farek Kelab.

Nobody claimed responsibility for the attack on the theater, which is popular with Westerners and close to the Doha English Speaking School.

Ali worked as a computer programmer for the state-owned Qatar Petroleum Co., according to an employee of the firm, who spoke on condition of anonymity.

Ali, who was in his 30s, had worked there for five years and was married with two children, the employee said, adding that police had visited the company’s offices Sunday and seized Ali’s computer and other belongings.

Security was heightened in Doha, the capital, on Sunday with extra checks at hotel entrances and police patrols in the streets.

In Cairo, a government official declined to comment on the bomber’s alleged nationality, saying only the Egyptian Embassy in Doha was seeking further details.

Ali’s uncle, Mohammed Abdullah, told reporters who went to the family home in the Sayeda Zeinab district of Cairo that his nephew could not have carried out the suicide attack as he had spoken to him by telephone after the assault.

Qatar, an energy-rich country with a population of about 800,000, is a close ally of America and home to the U.S. Central Command’s forward operations in the Middle East, which played a central role in the March 19 invasion of Iraq in 2003.

The blast occurred in the middle of a performance of Shakespeare’s “Twelfth Night.” The largely European audience streamed out of the hall afterward.

A Briton, Jonathan Adams, was killed in the attack, according to the British Foreign Office. A dozen others, including six Qataris, a Briton, an Eritrean, and a Somali, were injured and had already been released from the hospital, Qatari officials said.

Americans were in the theater audience, but none were known to have been injured, U.S. Embassy spokeswoman Patricia Kabra said.

The American school and several other international schools in Doha closed on Sunday, a regular working day in the Gulf, awaiting news of the investigation, Ms. Kabra said.

The explosion “was the result of a criminal operation carried out” by Ali who detonated his car bomb from behind a brick wall close to the theater, the Interior Ministry said. Wooden buildings in the theater compound were set afire and the main theater building was slightly damaged.

The British Foreign Office said British authorities were assisting Qatar in the bombing investigation, and France’s President Chirac said he would send a team of experts to help with the investigation.

The Gulf Cooperation Council, an alliance of six Arab states including Qatar, said in a statement the attack was a “criminal, vicious act” that ran counter to all religions and moral values.

A Saudi militant who is believed to lead Al Qaeda in the Gulf, Saleh al-Aoofi, released an audiotape on Thursday that urged militants to attack Westerners in Qatar and other countries.

“To the brothers in Qatar, Bahrain, Oman, the Emirates, and to all the lions of jihad in the countries neighboring Iraq, every one of us has to attack what is available in his country of soldiers, vehicles and air bases of the crusaders and the oil allocated for them,” according to an excerpt from tape published in Sunday’s London-based Asharq al-Awsat newspaper.

Al-Aoofi is named on Saudi Arabia’s list of the 26 most wanted terror suspects.

The last such attack in Qatar occurred in February 2004 when a car bomb killed Zelimkhan Yandarbiyev, a rebel leader and former Chechen president who had taken refuge in the country. Two Russian intelligence officers were convicted of the murder and sentenced to 25 years in prison.