(CNN) -- A pro-Taliban cleric who helped negotiate a short-lived cease-fire between the militant organization and the Pakistani government was arrested Sunday in Pakistan's North West Frontier Province.
Sufi Muhammad, the head of the banned jihadi organization Tehreek e Nifaz e Shariat Muhammadi (TNSM) -- which translates as the Movement for the Enforcement of Islamic Sharia Law -- was detained in the town of Seethi, near Peshawar, intelligence and police sources told CNN.
Muhammad's two sons, Rizwanullah and Ziaullah, and one friend, Mulvi Tahir, were also arrested. North West Frontier Province officials confirmed Muhammad's arrest, though not the reason for his detention, at a news conference in Peshawar.
In February, Muhammad acted as an intermediary between the government and the Taliban in negotiations over a cease fire in return for the imposition of Sharia law in the Swat Valley.
However, the agreement was short-lived and in April he withdrew his support, claiming that the government was not holding its side of the agreement.
Muhammad had been jailed by Pakistan authorities previously and was released in 2008 after agreeing to renounce violence and work towards peace.
He is also the father-in-law of Maulana Fazullah, the leader of the Taliban in Pakistan's Swat Valley.
Violence in the Swat Valley has had devastating affect on the region's residents.
The United Nations estimates that 375,000 Swat Valley residents fled their homes during the fighting. In all, 2.5 million Pakistanis were displaced in what was said to be one of the largest human migrations in recent history.
About 260,000 people have been living in 21 refugee camps in neighboring Mardan, Swabi, Nowshera, Peshawar and Charssada districts, but the United Nations High Commissioner for Refugees says the "vast majority" of internally displaced Pakistanis have been staying with host families, in rented homes or in schools.
Journalist Janullah Hashimzada in Peshawar contributed to this report.