Terror, Visible

Last week, Southeast Asia's war on terror, usually waged behind the scenes, burst into the open. In the Philippines, 22 alleged Muslim militants, including three top leaders of the Abu Sayyaf group, were killed during the bloody suppression of a prison riot. But offstage developments are just as frightening. TIME has learned that Philippine security forces seized a cache of sophisticated bombs during a mid-February raid on a safe house that police say was maintained by Abu Sayyaf in Manila. Twelve bombs manufactured from C4 plastic explosive were recovered, expertly hidden in items such as toothpaste tubes and deodorant bottles. "We call them invisible bombs because they are very, very difficult to detect," says one senior government official familiar with the case. "And at that size we can only think of one purpose: airplanes." The bombs, some of which already had detonators attached, represent a new level of danger for Asia's aviation industry.

Even more threatening than bombs or guns are those who might wield them. Malaysian security officials in Kuala Lumpur say five armed Thai Muslim militants were arrested at the city's central train station on March 9. Perhaps in an indication of the sensitivity of the arrests, Malaysian police spokesmen denied they had taken place. But TIME confirmed the incident with two Malaysian intelligence officials familiar with the case. Details of the arrest and what, if anything, the group had planned remained sketchy. But the intelligence sources say the Thais' presence in Kuala Lumpur, which has so far been spared a terrorist attack, is a disturbing sign. Malaysia recently arrested what police say is a top Thai militant leader, as part of a crackdown aimed at preventing rebels from slipping over the porous border between the two countries. Thailand has in the past complained that rebels use Malaysia as a refuge. "We were safe when Malaysia was seen as a place to hide," says a Malaysian intelligence officer. "But now we are arresting militants, and they are angry."