A female suicide bomber, believed to be a Tamil Tiger rebel and pretending to be pregnant to conceal explosives, set off a bomb Tuesday in front of a car that was taking Sri Lanka's top military general inside the army headquarters, the military said. The blast killed eight people and wounded 27 others, military spokesman Brig. Prasad Samarasinghe said. Lt. Gen. Sarath Fonseka suffered serious abdominal injuries, a hospital official said, adding that 10 surgeons were attending to him. The bomber died on the spot, but it was not clear whether she was included in the figure of eight dead given by Samarasinghe. "He is not out of danger, we are operating on him now," said Dr. Hector Weerasinghe of Colombo's National Hospital said of Fonseka. Fonseka, a battle-hardened soldier with 35 years in the infantry, was appointed to the top post after President Mahinda Rajapakse took office in November. The victims included civilians who visit the army headquarters complex in Colombo to meet relatives, Samarasinghe said. The attack was certain to put further pressure on the country's four-year-old cease-fire, which has been threatened by rising violence that has killed at least 89 people this month, including at least 43 soldiers or police. The woman was able to enter the area by presenting fake identification and saying she had an appointment for a pregnancy examination at the army hospital located inside the complex, said other officials, speaking on condition of anonymity due to military regulations. "I saw a fireball as I came out of my saloon," said S.A. Weerasinghe, who works in the military saloon, which is also inside the sprawling complex. Top Sri Lankan military officials work in the headquarters, which is protected by fences and troops guarding all entry points. There was no claim of responsibility. The Liberation Tigers of Tamil Eelam rarely take credit for such attacks. The rebels are known for their deadly suicide bombers, called Black Tigers. The first suicide attack by the guerrillas was in July 1987, when a rebel known as Captain Miller drove a truckload of explosives into a military camp, killing 40 soldiers. Since then, 240 other rebels have blown themselves up in attacks that have killed Sri Lankan President Ranasinghe Premadasa, former Indian Prime Minister Rajiv Gandhi and dozens of others. In earlier violence late Monday, suspected rebels in a hijacked bus opened fire on soldiers when their vehicle was blocked at a checkpoint in northern Sri Lanka, drawing return fire that killed the driver, the military said. The passengers on the bus - believed to be three or four Tamil Tiger rebels - escaped following the brief gunbattle in Jaffna, said Brig. Prasad Samarasinghe. Last week, the rebels backed out of peace talks scheduled to start Monday in Geneva, citing attacks on ethnic Tamil civilians and other disputes with the government. The Tamil Tigers are demanding a separate Tamil homeland and accuse the Sinhalese-dominated government of discrimination. A Norwegian-brokered cease-fire halted the war in 2002.