One of the suspected planners of last month's attack by gunmen on Mumbai was arrested by Pakistani security forces in a raid on a militant camp, an official with a charity linked to the militant group said on Monday. The Jamaat-ud-Dawa (JuD) official, who requested anonymity because of the sensitivity of the subject, said Zaki-ur-Rehman Lakhvi was taken into custody following Sunday's raid on a camp used by Lashkar-e-Taiba fighters outside Muzaffarabad, the capital of Pakistani Kashmir. "Yes, Lakhvi is among four or five people arrested in a raid yesterday," said the official, whose JuD charity is regarded as front for the feared militant group. Pakistani intelligence officers said six men have been arrested, but gave no names, and there has been no official confirmation of the raid. Lakhvi, one of Lashkar's operations chiefs, was named as a ringleader in the Mumbai plot by the lone surviving gunman captured in India, according to Indian officials. If Lakhvi's arrest is officially confirmed, it will raise the question of what the Pakistani authorities will do with him, and whether it will satisfy India. President Asif Ali Zardari has said that anyone arrested in Pakistan will be tried there too. Analysts say there is evidence of Lashkar fighters cooperating with al Qaeda, and fears that these jihadi organizations have become uncontrollable. The JuD charity, which has thousands of followers, was also designated a militant organization by the United States, but Pakistan has only put it on a watchlist.