Islamabad, June 22 (AP): The Pakistan army is questioning four more officers about suspected links with a banned extremist group that has called for the military to oust the country’s government, the army spokesman said today.

A day earlier, the army said it detained a senior officer working at army headquarters, Brig. Ali Khan, for suspected links with the group, Hizb-ut-Tahrir. The four army majors who are being questioned have not been detained, said army spokesman Maj. Gen. Athar Abbas.

The family of the arrested brigadier has denied he has any ties with extremist groups and has demanded he be released. A brigadier is the equivalent of a one-star general in the US.

Khan’s lawyer, retired Col. Inam Rahim, claimed that his client was arrested for demanding that someone within the military be held accountable for the covert US Navy SEAL raid that killed Osama bin Laden last month in the army town of Abbottabad not far from Islamabad.

The raid humiliated the Pakistani military, which did not know about it beforehand, and raised questions about how Osama could have lived in Abbottabad for five years without authorities knowing.

The army did not reveal the names of the four majors who are being questioned about suspected links to Hizb-ut-Tahrir.

Tahrir’s spokesman in Pakistan could not be reached for comment.

Tahrir is an Islamist organisation that wants to re-establish the caliphate, the administrative structure that once governed a large section of the Muslim world. It insists it has rejected violence, although observers say the group promotes an intolerant mindset that can ultimately lead some followers to embrace militancy.

Although it is banned in some countries, including Pakistan and parts of Central Asia, the group is active in western countries such as the US.

Analysts say the Pakistani army is better than the country’s police at rooting out extremists, but current and former military officers have participated in attacks in recent years. Faisal Shahzad, the Pakistani-American who tried to bomb New York city’s Times Square last year, allegedly was in contact with a major in the Pakistani military.

In 2009, Pakistani army headquarters in Rawalpindi was attacked by 10 men in military uniforms reportedly led by a former soldier.

Also, the 2008 attacks in Mumbai are alleged to have been carried out with the guidance of a Pakistani spy known only as “Major Iqbal”. One constant fear is that extremists in the military could somehow infiltrate Pakistan’s nuclear programme to steal materials.