Land-mines planted by Islamic militants are slowing efforts to secure the release of an Italian Red Cross worker being held hostage in Jolo, a senior cabinet official said Tuesday.

The involvement of foreign Islamic militants believed to be aiding the Abu Sayyaf group was also complicating efforts to end the hostage crisis on Jolo, Interior Secretary Ronaldo Puno said.

Intelligence reports indicate that the hostage, Eugenio Vagni, is still alive but being moved around, Puno said. He said land-mines planted by the Abu Sayyaf were slowing down troops hunting for the kidnappers.

"The matter is complicated by the fact that some international terrorists are moving with them," Puno told the Foreign Correspondents Association of the Philippines.

"This is emboldening them and at the same time it is making them more recalcitrant and harder to talk to," he said.

One of those believed to be aiding the Abu Sayyaf is Umar Patek, an Indonesian member of Jemaah Islamiyah wanted over the 2002 Bali bombings.

Vagni, 62, was kidnapped along with fellow International Committee of the Red Cross (ICRC) workers Mary Jean Lacaba of the Philippines and Andreas Notter of Switzerland in January.

Lacaba and Notter were released in April, allegedly after a ransom was paid.

Puno said troops and police were continuing to pursue the kidnappers while negotiators aided by Islamic religious leaders were also working to secure Vagni's release.

"We are hopeful we will have a release of Mr Vagni soon because all sides are tired," he said. "There are serious discussions going on now."