Image caption The group has held a series of anti-US rallies in Pakistan's largest cities

Pakistan's government has issued orders banning the country's largest Islamic extremist group.

Ahle Sunnah Wal Jamaat was first banned in 2002 by then Pakistani leader Gen Pervez Musharraf.

Activists from the pro-al-Qaeda group formerly known as the Sipah-e-Sahaba (SSP), or Soldiers of the Companions of the Prophet, have been convicted of killing hundreds of Shia Muslims.

The head of the group described the ban as preposterous.

Other minorities, security targets and embassies have also been targeted by members of the group.

The group has also recently been in the forefront of an alliance of extremist groups calling for an end to the country's relationship with the US, the Defence of Pakistan Council (Difa).

'Preposterous'

The notification ordering the ban was issued to relevant security departments two weeks ago but no public announcement has yet been made.

The interior ministry's order says the organisation has been banned for what it calls its "concerns in terrorism", according to a copy of the order obtained by the BBC.

Despite repeated attempts to contact Rahman Malik, the country's interior minister, he was unavailable for comment.

But the head of the Ahle Sunnah Wal Jamaat group, Maulana Mohammad Ahmed Ludhianvi, told the BBC that the group intended to challenge the order in court.

"It's taken us so long so rein in our activists - it will become very difficult to control their emotions if the ban is enforced," he said.

Militant attacks

After the last ban, many of the organisation's activists went underground and allied themselves with other militant groups to carry out attacks across Pakistan.

The SSP has always maintained that these activists joined a splinter faction of the group called Lashkar-e-Jhangvi.

But security officials in Pakistan and beyond maintain that the groups are one and the same.

They allege that beneath the guise of Lashkar-e-Jhangvi, the SSP has been behind most of the major militants attacks in Pakistan, including the assassination of former Prime Minister Benazir Bhutto.

The group is also said to be responsible for the continuing killing of members of the country's minority communities, particularly Shia, across Pakistan.

Recently, however, the group has attempted a kind of rehabilitation - renaming itself Ahle Sunnah Wal Jamaat and trying to act like a mainstream political party.

As part of the Defence of Pakistan Council, it has held rallies in all of the country's major cities - including Karachi, Lahore and Rawalpindi - and calling on the government to cut off all ties with the US and the West.

The largest rally was recently held in Karachi. Afterwards, the US State Department called on the Pakistan government to implement bans on such groups, in particular Jamaat-ud-Dawa.

It said the group was a front for Lashkar-e-Taiba, which was held responsible for the November 2008 attacks on India's business capital, Mumbai.

Although the Jamaat-ud-Dawa remains absent from the order, it appears some of the US pressure has paid off.

"American and pro-American elements are afraid of the Difa and have orchestrated this ban," Maulana Ludhianvi says.

"In essence, whoever enforces the ban is enforcing their will on Pakistan," he added, pledging that he would never allow that to happen.