Two men suspected of planting bombs in the southern Philippines city of Davao last year have been arrested, authorities said on Thursday.
The latest suspects were paraded before the media
The Philippines military said the pair were linked to regional Muslim militant group Jemaah Islamiah (JI).
But a spokesman for the country's largest militant group, the MILF, denied the two had done anything wrong or had links to JI.
The two Davao bombings killed 38 people and injured more than 150.
Rahman Camili, also known as Barok, is suspected of planting a bomb outside Davao airport on 4 March 2003 which killed 22 people and injured more than 100.
Rio Dimson Manamba, also known as Bobot, is accused of planting a bomb a month later - on 2 April 2003 - in Davao's busy wharf area, killing 16 people and injured more than 50 others.
The two men were paraded before reporters in a Manila military camp.
They were arrested on the basis of information provided by previously arrested suspects.
A spokesman for the MILF, which is currently under ceasefire and has been involved in peace talks with the government, said that the group would protest against the arrests when government and MILF truce panels meet next week.
"They have not done anything wrong," Eid Kabalu told Reuters news agency. "They are our members and the MILF is not involved in any terrorist attack. They are making a big mistake," he said.
The military says the attacks were ordered and financed by a man called Zulkifli, a senior leader of Jemaah Islamiah, the Muslim militant group blamed for a series of attacks across the region, including the 2002 Bali bombings.
Zulkifli was arrested in Malaysia last year.
Last month, three more suspects in the Davao attacks were arrested, having allegedly confessed to taking part in the bombings.
Mindanao is mired in factional fighting, with government troops clashing regularly with a series of Muslim separatist rebel groups.