ISLAMABAD, July 27 (Xinhua) -- Pakistan began investigating Monday the detained Maulana Sufi Muhammad, chief of a banned group, and the cleric admitted his speaking publicly against the state, local TV channel reported .

    "The federal government has set up an investigation team of security agencies and Sufi Mohammad will be formally charged on the basis of its findings," said Arshad Abdullah, law minister in North West Frontier Province (NWFP), according to the private TV channel Dawn News.

    Ameer Haider Khan Hoti, Chief Minister of NWFP, was quoted as saying that Sufi Muhammad has admitted his speaking publicly against the state.

    Meanwhile, Pakistani Interior Minister Rehman Malik said until the completion of the investigation Sufi Mohammad will remain in police custody.

    Sufi Mohammad, chief of Tehrik-i-Nifaz-i-Shariat-i-Muhammadi (TNSM), who brokered a deal between the government and the Taliban early this year, was arrested Sunday on the outskirts of Peshawar.

    It was reported that Sufi Muhammad created favorable situations for terrorism in Malakand of the NWFP. He assured that militants would lay down arms but criticized the country's judiciary system and promoted terrorism in the area.

    In February, the NWFP government and the Taliban made a deal for the implementation of Shariat, Islamic laws, in the Malakand region as long as Taliban lay down arms.

    On April 13, Pakistani President Asif Ali Zardari gave the go-ahead to the NWFP government to enforce Shariat laws in the Malakand region, including Swat after the deal was passed by the National Assembly, the lower house of the Pakistani parliament.

    Pakistani security forces launched the military operation against Taliban militants late April after militants entered the Buner district from the neighboring Swat and refused to vacate the area despite their pledge to do so.