A female suicide bomber detonated her explosives-laden vest near a Shiite shrine killing at least 36 people on Monday in the central Iraqi city of Karbala, police and health officials told AFP.

The attack came as US Vice President Dick Cheney visited Baghdad on a surprise trip and met several US and Iraqi leaders to discuss the recent improvement in security across the country.

At least 50 people were wounded in the blast which occurred near the revered Imam Hussein shrine, said Alaa Hamud Dadair, head of Karbala's health directorate.

The bomber was a woman, a local police officer said on condition of anonymity, adding she blew herself up near the shrine among a crowd of people.

An AFP correspondent at the site said several ambulances and police vehicles ferried victims to hospital following the blast which occurred around 100 meters (yards) from the shrine, located in the centre of the city.

The correspondent said the powerful explosion ripped people apart, sending body parts flying. Many bodies were charred.

Salim Kadhim, spokesman for the Karbala health directorate, said seven Iranian pilgrims were among those wounded in the blast.

Soon after the attack, police in Karbala, 110 kilometers (70 miles) south of Baghdad, imposed an indefinite curfew in the central districts of the city.

On April 28 last year, a suicide car bomb attack near the Imam Abbas shrine, a second revered shrine in Karbala, killed more than 70 people and wounded nearly 160.

Two weeks earlier, a similar bomb attack close to the Imam Hussein shrine killed 42 people and wounded scores more.

Karbala was also the site of bloody clashes between Shiite militants and police in August which left more than 50 people dead and hundreds injured.

The Mahdi Army militia of Shiite cleric Moqtada al-Sadr was blamed for those clashes after which Sadr ordered a freeze on the activities of the militia, which remains in force.

Iraq has been rocked by a series of suicide bomb attacks in recent months, including by females.

The US military says explosive vest has become the weapon of choice for Al-Qaeda in Iraq.

"Late in 2007 there were about eight or 10 (suicide bombings) a month; in the month of February, there were 18. There is an increase," US military spokesman Rear Admiral Gregory Smith told a news conference on Sunday.

PHOTO CAPTION 

Iraqi Shiite pilgrims gather around the Shrine of Imam Hussein for the ceremony of Arbaeen in Karbala, in February 2008.

AFP