MANILA, Philippines -- Abu Sayyaf bandits holding an Italian Red Cross worker hostage are reportedly trying to link up with one of their leaders, Radullan Sahiron, Interior and Local Government Secretary Ronaldo Puno said on Monday.

Numbering around 50, the group holding Eugenio Vagni was trying to slip past a military cordon and join Sahiron’s group in Patikul town, where they will be more difficult to catch because of the rough terrain, Puno told a news conference in Camp Crame.

“If they link up with Sahiron, Sahiron has a much bigger group than Doctor Abu,” Puno said, referring to one of the leaders of the hostage-takers.

“And you know the terrain in Patikul is much, much more difficult… If they reach Patikul, it will be twice as difficult as [operations] in Indanan and Parang [towns],” he said.

Two other volunteers from International Committee of the Red Cross (ICRC), which were seized by the Abu Sayyaf alongside Vagni on Jolo Island last January 15 have been freed.

Swiss national Andreas Notter was freed last Saturday while Filipina engineer Mary Jean Lacaba was released last April 2.

Prior to Notter’s release, the kidnappers have reportedly split into three small group. The first group remained in the vicinity of Mt. Tucay; a larger group with Abu Sayyaf leader Albader Parad which was holding Vagni headed west; while a small group composed of seven bandits headed east towards Indanan town, where Notter reportedly gave his captors the slip.

Puno said government troops would tighten the cordon surrounding the kidnappers.