Multiple bombs rock Iraqi city of Najaf

A wounded man is seen after a bombing in Najaf, Iraq

The three bombs struck simultaneously

Three bombs have exploded in the Iraqi city of Najaf, killing at least 15 people and wounding dozens of others, security sources say.

Initial reports suggested that the bombs were detonated near a market in the city centre, filled with shoppers in the early evening.

The mainly Shia city, some 90 miles (150km) south of Baghdad, attracts thousands of pilgrims each year.

It is home to the mausoleum of Imam Ali, cousin of the Prophet Mohammed.

"Three bombs exploded at the same time close to a large market at Jumla, targeting the innocent, passers-by and traders," a local government official said, according to the AFP news agency.

He said those injured in the triple blasts were being taken to hospital for treatment.

A police source in Baghdad said the blasts had occurred less than a kilometre from the Imam Ali shrine, Reuters reports.

Iraqi security forces sealed many of the main roads into the city following the attack, AFP reports.

Although attacks are common in the capital, Baghdad, as well as in the northern cities of Mosul and Kirkuk, violence in Najaf has become rare.

The last major attack in the city dates back to February 2007 when a suicide car bomber struck an Iraqi police checkpoint, killing 13 people and wounding dozens more.