Malaysian security forces on Tuesday began attacking a group of armed men from the Philippines who had clashed with police after staking a claim to a remote part of the island of Borneo, authorities said. The group of Filipino men, believed to number between 100 and 300, arrived three weeks ago on the east coast of the Malaysian state of Sabah, on Borneo, demanding to be recognized as representatives of a sultanate that used to rule the area. Malaysian authorities initially tried to persuade the men to return peacefully to their homes in the nearby southern Philippines. But the intruders...