MANILA - An Italian Red Cross worker held hostage by Islamic militants in the southern Philippines is still alive, the military said Sunday, after weekend clashes left six members of the security forces dead.

"Our information is clear, that he is alive," Marine spokesman Lieutenant Colonel Edgar Arevalo told a Manila radio station, citing intelligence reports from the field.

He said troops were conducting follow-up operations Sunday, a day after five Marines and a police commando were killed in an ambush by Abu Sayyaf militants, who have been holding Eugenio Vagni, 62, on southern Jolo island since January.

Arevalo said 17 soldiers were also wounded in the fighting, although the Abu Sayyaf was believed to have suffered heavy casualties as well.

"We are conducting surgical, deliberate operations," Arevalo said.

The latest verifiable information from the area indicated that Vagni, who is said to be suffering from a hernia, was being moved around by his captors in Jolo's jungles.

Vagni was seized along with fellow International Committee of the Red Cross (ICRC) colleagues Andreas Notter of Switzerland and Mary Jean Lacaba of the Philippines in early January while on a humanitarian mission on Jolo.

Notter and Lacaba were released in April, although efforts to negotiate Vagni's release have been exhausted, Arevalo said.

Formed in the early 1990s ostensibly to fight for an Islamic state in the south, the Abu Sayyaf over the years has increasingly turned to kidnapping.

It is on the US government's list of foreign terrorist organizations, and has been blamed for high profile kidnappings and the country's worst militant attacks, including a 2004 bombing of a ferry that left over 100 dead.