Unknown assailants hurled a bomb to stop a commuter van in Thailand's restive south Wednesday, then shot its nine passengers execution-style, killing eight of them, military and hospital officials said. The cold-blooded attack came after officials announced they were stepping up security in the south, where a regional insurgency has claimed more than 2,000 lives since 2004, The Associated Press reported. Suspected insurgents bombed the van as it slowed into a curve in the road, which they had also blocked with a large tree trunk, said police Lt. Kitti Mankhong, a duty officer in the Yaha district of Yala province, where the attack occurred. Armed with assault rifles, the attackers first shot at the driver and then opened the side door of the van and fired at each of the passengers, he said. The driver, who was hospitalized with a gunshot wound to the face, survived the morning attack, as did one passenger.