President Benigno Aquino said Sunday that negotiations were the only way to resolve a Philippine sultanate's claim to Sabah as he criticised an armed incursion into the Malaysian state. Aquino also lashed out at unidentified conspirators whom he accused of sending the sultanate's followers to Sabah last month, saying they had endangered some 800,000 Filipinos living and working in the area. Speaking at the elite Philippine Military Academy, the president criticised anew the followers of the self-declared Sultan of Sulu, Jamalul Kiram III, whose incursion into Sabah has led to dozens of deaths. "There are problems that just beget more problems if you try to solve them with haste or force. We need sincere and deep discussion if we are to arrive at a correct solution," he told graduating military cadets. "We already know how complicated this issue is. Could any Malaysian prime minister so easily agree to let go of a land that for so long has been subject to their laws?" Aquino asked. More than 200 followers of Kiram, some of them armed, entered Sabah to reassert the sultanate's centuries-old claim to the area. Fighting with Malaysian security forces broke out on March 5 and according to Malaysian police figures, 61 of the intruders as well as eight police officers and a soldier have died. Authorities have arrested more than 100 people in Sabah on suspicion of having links to the militants. The Philippine Navy last week detained 35 suspected Filipino intruders as they tried to sail home. However Agbimuddin Kiram, the leader of the intruders and the younger brother of Jamalul Kiram III, was not among those detained. Aquino hinted that the Kirams had hidden backers, saying the incursion in Sabah must have cost a large sum of money. The spokesman for the Kiram family, Abraham Idjirani, said that the sultanate was forced to take action because the Philippine government would not act on their claim. He also denied anyone had financed the trip, saying the sultan's followers did so on their own. Idjirani said he had spoken to Agbimuddin Kiram by phone late Saturday and he was still in Sabah and unharmed.