Three Malaysian and Indonesian seamen kidnapped by Philippine Abu Sayyaf kidnap-for-ransom group allegedly had been executed and the skeletons discovered in the southern Philippines are believed to be their remains, a local television reported Wednesday.

The skeletal remains were found three weeks ago in shallow graves on Tawi Tawi island in the southern Philippines after two captured gunmen of the Abu Sayyaf group led the military to the grave, the ABS-CBN news channel reported, quoting a Philippine marine source.

"The remains have been flown from the Philippines Marine 11 battalion base Camp in Sanga Sanga on Tawi Tawi island to the southern command military headquarters in Zamboanga city for DNA tests," a Philippine official said on condition of anonymity.

A postmortem would be conducted to determine the cause of death and to confirm that the skeletal remains were those of the three abducted seamen, he added.

The sailors -- Malaysians Toh Chiu Tiong and Wong Siu Ung and Indonesian Walter Sempel -- were abducted when their tugboat was attacked on its way from Miri in Malaysia's Sarawak state to the Solomon Islands on April 11.

The Abu Sayyaf, allegedly linked to the Al-Qaeda network of Osama bin Laden and known mainly for kidnapping for ransom and bomb attacks, has been listed as a terrorist group by both the US and Philippine governments.

Source: Xinhua