Pakistan's Interior Minister Rehman Malik has said federal authorities would be forced to act if the Punjab government does not crack down on the banned Lashkar-e-Jhangvi, responsible for a series of attacks on the minority Shia sect.

Malik said he had written a letter to the government of Punjab, which is ruled by the PML-N, urging it to take action against the LeJ.

He said some 3,000 members of banned groups were active in Punjab and they should be placed under house arrest or detained.

The LeJ has its headquarters in Punjab and the provincial government should act against it, Malik said, while interacting with reporters outside parliament yesterday.

"I have written to them to take action. If they don't do anything, I may have to use federal agencies (to take action)," he said.

The LeJ claimed responsibility for a devastating bomb attack in a Shia-dominated area of the southwestern city of Quetta that killed 89 people and injured nearly 200.

The group was also behind twin suicide bombings in the capital of Balochistan province that killed 92 Hazara Shias last month.

The federal government sacked the Balochistan government last month and imposed Governor's Rule.

However, a LeJ spokesman has said such steps would not deter the group from continuing its attacks on Shias.

The PML-N and the Pakistan People's Party-led federal government have been at loggerheads on the issue of tackling militant groups like the LeJ, Jaish-e-Mohammed, Lashkar-e-Taiba and Sipah-e-Sahaba that are active in Punjab.

Several PML-N leaders, including Punjab Law Minister Rana Sanaullah, have been accused of maintaining links with banned groups.