Malaysia has pressed terrorism-related charges against members of a Philippine armed group who clashed with security forces after landing in a remote coastal area of Sabah and pressing a 19th century claim to the land.
The eight Filipinos could face life imprisonment, or death penalty the Malaysian state news agency Bernama said on Wednesday.
The men, aged between 17 and 66, appeared in a heavily guarded court in the coastal town of Lahad Datu, site of most of the fighting.
The men entered no plea.
Security forces are still hunting down the remnants of the group called Royal Sulu Army that sailed in mid-February to Borneo island, eventually triggering battles that left up to 71 dead.
Nine of the dead were Malaysian security peronnel.
Neither police nor the attorney general's office could be reached for comment.
Malaysian Prime Minister Najib Razak has been under pressure to take a tough stand after security forces took no action against the intruders for two weeks.
Najib must call a national election in weeks and his party, in power since independence from Britain in 1957, faces a tough contest.
Ties between Malaysia and the neighbouring Philippines, periodically strained by security and migration issues, could be further soured by the case.
Philippine President Benigno Aquino III also came under heavy domestic criticism for the death of the Filipino citizens, and for not backing the Sabah claim.
The group of about 200 engaged in weeks of negotiations over their claim to the region before Malaysian forces mounted an all-out assault in oil palm-fringed coastal areas.
Militants who escaped the onslaught went into hiding, surfacing occasionally for gun battles with Malaysian forces.
The Filipino group is demanding recognition and increased payment from Malaysia for their claim to Sabah, part of Borneo leased by the Sultanate of Sulu to British colonialists in the 19th century.
Members say they are a part of the Sultan of Sulu's army and offered a unilateral ceasefire rejected by Najib.
There are an estimated 800,000 Filipinos living in Sabah, making up about a quarter of the population of the state, which is just about 30-minute boat ride from the southern Philippines.
Many of the Filipinos have since been forced back to the Philippines following the month-long fighting.