Lawyers for Juan Ponce Enrile asked the Supreme Court on Wednesday to free the opposition senator, who was arrested on charges of backing December's failed coup. Vice President Salvador Laurel described the arrest of the former defense minister as an attempt to silence the opposition. Laurel broke with President Corazon Aquino in 1987 and later joined Enrile in forming the opposition Nacionalista Party. ``It could only be the beginning,'' Laurel told reporters. ``It is not the end. We are bracing for that. We are prepared for the worst. ... I think Mrs. Aquino is exacerbating the fragmentation and disunity of the nation.'' Enrile, who played a key role in bringing Mrs. Aquino to power in a 1986 uprising, was arrested Tuesday, held overnight at the National Bureau of Investigation, and transferred early Wednesday to police headquarters in suburban Quezon City. He faces charges of ``rebellion with murder.'' Military dissidents claimed the arrest of one of the administration's sharpest critics was a prelude to martial law. In a petition filed Wednesday, Enrile's law partner, Renato Cayetano, claimed the arrest was illegal and violated the senator's rights. The petition asked that Enrile be freed. Court officials said no hearing had been scheduled. Also Wednesday, three senators filed a proposal asking judicial authorities to place Enrile under the custody of the Senate's sergeant-at-arms to allow the lone opposition senator to attend sessions. Enrile, who was among seven people indicted Tuesday, denied any role in the Dec. 1-9 coup attempt that left at least 113 people dead and wounded more than 600. Indicted with 66-year-old Enrile, were dismissed Lt. Col. Gregorio ``Gringo'' Honasan; Rodolfo Aguinaldo, suspended governor of Cagayan province; ret. Brig. Gen. Felix Brawner; retired Lt. Col. Billy Bibit; and businessman Rebecco Panlilio and his wife, Erlinda. In the northern province of Cagayan, a local government official said Aguinaldo, a former army lieutenant colonel, was reported to have gone in hiding after learning late Tuesday that an arrest warrant would be served on him the next day. Enrile is the most prominent figure charged in any of the six coup attempts since Mrs. Aquino was swept to power in February 1986 by the military-popular uprising that drove the late President Ferdinand E. Marcos into exile. Troops went on alert in the Manila area Tuesday to prevent possible reprisals after the arrest, according to presidential spokesman Tomas Gomez. On Wednesday, police defused a homemade bomb outside a shopping center in Manila's financial district of Makati. Police said they did not know who placed the bomb. Enrile was defense minister under Marcos but turned against him and led the military mutiny that prompted the uprising. He kept the post under Mrs. Aquino, but he was fired in November 1986 after a coup attempt by his followers. A spokesman for soldiers involved in the December coup said the nation ``should brace itself for the imminent declaration of martial law.'' However, in a radio interview Wednesday, Gomez said the charges were justified because Enrile led ``the numerous attempts at a coup d'etat to destroy this government of ours.'' Enrile was arrested after three witnesses claimed they saw Honasan and about 100 rebels at Enrile's home on the first day of the failed coup. The senator claims not to have seen Honasan, his former protege, since 1987.