Manila- Philippine security forces have lost track of an ailing Italian Red Cross worker held by Muslim militants on a southern island for over 100 days, a Marine spokesman acknowledged Monday. Lieutenant Colonel Edgard Arevalo appealed for public "patience and understanding" as security forces tried to determine the exact location of Eugenio Vagni, a staffer of the International Committee of the Red Cross.

The 62-year-old Vagni, who reportedly needs medical attention due to a hernia injury, has been held captive by Muslim Abu Sayyaf rebels in the the jungles of Jolo island,
1,000 kilometres south of Manila, since January 15.

"The military continues to intensify intelligence gathering to ensure that it has certainty as to the exact whereabouts of the kidnap victim and his captors," Arevalo said.

"The public can trust the military commanders in Jolo who are now in charge of military operations that they are in control," he added. "They have the training, experience and maturity to prudently and adroitly deal with the situation."

Vagni was abducted along with two Red Cross colleagues, Swiss national Andreas Notter and Filipino Mary Jean Lacaba after they visited the Jolo provincial jail to oversee a water and sanitation project.

The rebels freed Lacaba on April 2 and Notter on April 17.

Governor Abdusakur Tan, who heads a committee handling the hostage crisis, ordered the military to launch rescue operations to save Vagni shortly after Notter was freed.

But those efforts have been hampered by lack of information on where Vagni was being held by the kidnappers.

The government last week offered a 500,000-peso (10,256-dollar) reward for information on his location following reports that the Italian had been abandoned by his captors.

Arevalo said the rebels were suspected to have hidden to evade the military operations.

"The fact that the terrorist group already knew that there's nothing that will prevent the security forces from hitting them at an opportune time is already a pressure strong enough for them to flee," he said.

The Abu Sayyaf rebels have been blamed for some of the worst terrorist attacks and high-profile kidnappings in the Philippines. They have beheaded hostages, including an American tourist abducted in 2001, when authorities failed to meet their demands.(dpa)