|Nikson (left) and Brown (right)|
Philippines intelligence sources said siblings Nikson and Brown were shot dead when they tried to escape after their capture at about 5am Tuesday near Pata municipality in Sulu province.
According to Philippines intelligence sources, the duo had grabbed the weapons of security personnel escorting them and opened fire on the soldiers.
The brothers were killed when the troops retaliated in the shootout.
There were no reports of injuries among the troops in the shooting that occurred around 8.30am.
Nixon and Brown had been lying low for the last six months after Philippines and Malaysian authorities stepped up the hunt for the notorious brothers, who are responsible for cross-border kidnappings and killings both in Sabah waters and the Philippines.
Of the other Muktadil brothers, Mindas was killed in late May by Jolo police and his twin Kadafi was arrested in Jolo on Nov 28 when he was admitted to hospital following a motorcycle accident. Only Badong is at large.
Kadafi, who is facing charges in the Philippines, is also being sought by Malaysia over the kidnapping of Bernard Then, 37, and Thien Nyuk Fun, 50, the manageress of Ocean King Seafood restaurant, in Sandakan on May 14 last year. Thien was released but Bernard was beheaded.
The Tawi Tawi-based group led by the Muktadil brothers have been involved in cross-border kidnappings since late 2013. They have taken hostages including tourists to Jolo where Abu Sayyaf gunmen demand ransom for their freedom.