Suspected Abu Sayyaf militants who abducted three Indonesian fishermen during the weekend had fled into the Philippine waters with the hostages, the chief of Indonesia's intelligence agency has said. The kidnapping is the latest in a series of such incidents, the most recent being reported in the third week of June.

Despite efforts by Indonesia, Malaysia and the Philippines to tighten security and patrolling of the waters in the region, abductions have continued. The countries are reportedly concerned that the rise in such kidnappings and piracy could dent their commerce.

Sutiyoso, the director of the State Intelligence Agency, said the fishermen were working on a Malaysian fishing boat off Lahad Datu in the Malaysian part of northern Borneo. The militants took the three fishermen hostage while some crew members from the fishing boat managed to escape and reached Malaysia.

"We are still investigating this case and continue to coordinate with the related institutions in the Philippines to find the location where the three hostages are being held," Sutiyoso told The Associated Press. He added: "We suspect that the hostages are held by a militant group which is part of the Abu Sayyaf network."

Suspected Abu Sayyaf militants were reported to have taken hostage seven Indonesian sailors in the Sulu Sea in the southern Philippines around 24 June. AP reported that the Indonesians were held captive in the jungles of Sulu province and later released. The Indonesian government denied having paid any ransom for their release.

Earlier, Abu Sayyaf beheaded two Canadian nationals – John Ridsel and Robert Hall – after the Canadian government refused to pay ransom.

The Philippines launched a major offensive following the executions and it was reported that up to nine Abu Sayyaf extremists were killed by Philippine troops, who used rocket-firing helicopters and artillery fire against the militants. The Thursday (7 July) fighting left one Philippine soldier dead and six wounded as they tried to battle about 130 Abu Sayyaf fighters in the jungles of the mountainous Patikul town in Sulu province, regional military spokesman Maj Filemon Tan had told AP.