Suspected Islamic separatists detonated a bomb in southern Thailand on Sunday, killing two police officers and wounding three other people, just hours after the country's queen appealed to the nation to condemn such attacks. The device, believed to have been triggered by a mobile phone, exploded in a small storehouse near a border police station and a market along the Malaysian frontier, said police Lt. Sittidej Ruansong. Two police officers were killed, while another officer and two villagers were wounded in the blast, he said.The attack in Narathiwat province came after Thailand's Queen Sirikit delivered a televised address late Saturday calling on the public to unite against the ongoing violence in the southern provinces, the only Muslim-dominated area of this largely Buddhist country. "We have to condemn such actions as being totally devoid of humanity," the queen was quoted as saying by the Bangkok Post. "We have to let these brutes know — without taking arms — what we feel." The queen said she was especially shocked by a recent string of bombings at an international airport, a superstore and a hotel in the southern city of Hat Yai. Two people were killed and more than 70 others wounded in the April 3 blasts.