KARACHI: Pakistani police said Friday that seven suspects from a feared Al-Qaeda-linked group had been arrested for allegedly plotting to attack school buses and prisons in Karachi.

"We have arrested seven men and recovered seven explosive-filled jackets, rockets and detonators," senior police official Aslam Khan told reporters.

"They were planning to hit school vans in Karachi to create anarchy and then attack prisons to get their comrades freed," he added.

Police arrested the men Friday in the western neighbourhood of Manghopir and Khan said they were members of banned sectarian group Lashkar-e-Jhangvi.

Karachi is Pakistan's largest city with an estimated population of 18 million. Its Arabian Sea port is used by the United States and NATO to ship supplies to the war in neighbouring, landlocked Afghanistan.

Lashkar-e-Jhangvi is regarded as one of the most brutal of Pakistan's sectarian groups and has been linked to strings of attacks on minority Shiite Muslims.

Afghan President Hamid Karzai last year blamed the group over the unprecedented bombing of a Kabul shrine which killed 55 people.

Pakistani authorities also accused the group over the 2008 attack on Islamabad's five-star Marriott hotel which left 60 people dead, and say the group has strong links to the Taliban and Al-Qaeda.