Updated

In chilling security camera footage, a female homicide bomber on a mission to kill a Sri Lankan Cabinet minister is seen patiently answering questions in a bustling government office before calmly standing up and detonating the bomb hidden in her bra.

The video, released by police Friday, gave a rare look at a homicide bomber's last moments and the immediate aftermath of a devastating attack.

• Click Here to See Photos of the Sri Lanka Homicide Attack (WARNING: Graphic Content)

In the footage, the bomber, wearing a yellow sari and a white shawl, calmly walked into a small waiting room at the Colombo offices of Social Services Minister Douglas Devananda on Wednesday, the day he sets aside to hear complaints from the public.

The woman, identified by police as 24-year-old Sujatha Vagawanam, sat down in front of a desk and answered questions from Devananda's 72-year-old aide Steven Peiris. As the two spoke, Peiris was repeatedly interrupted by other officials sitting nearby or walking past.

After nearly a minute and a half, he began gesturing for her to sit down in a nearby cluster of white plastic chairs, apparently to await a security check. She then stood up facing Peiris, reached her right hand to her right shoulder to grab something and exploded.

Peiris and the bomber, both of whom were killed, flew backward. The others in the room scrambled in all directions, some falling over their chairs in their haste to escape as a cloud of smoke hung in the air.

"She thought she was getting caught, so she exploded her bomb," said Devananda, the target of the attack.

Devananda, a Tamil politician seen as a rival to the Tamil Tiger rebel group, said the guerrillas had made more than 10 attempts on his life and killed more than 70 members of his Eelam People's Democratic Party in recent years.

A former Tamil militant group, the Eelam People's Democratic Party renounced violence and joined the political mainstream in 1987. The Tamil Tigers oppose the group.

"This is nothing new to me," he told The Associated Press in an interview at his heavily guarded home in Colombo. "I expect that these things happen, and will happen. It will continue."

The woman had aroused concerns in his office because she had not made an appointment and did not bring a letter of introduction from his office in her hometown of Vavuniya, on the edge of rebel-held territory, he said. Earlier police reports that she had suffered from polio and had a limp were incorrect, he said.

The rebels were also blamed for a second bombing Wednesday that killed 19 people at a department store in a Colombo suburb during the busy evening rush hour.

The government said the attacks proved the rebels were suffering from a military onslaught against their stronghold in northern Sri Lanka, security officials said.

"They were desperate and unable to face the security forces in the north," military spokesman Brig. Udaya Nanayakkara said.

The military announced Friday that it had killed 14 rebels the day before in a wave of fighting near the rebels' northern stronghold.

Rebel spokesman Rasiah Ilanthirayan, who has not answered repeated calls from The Associated Press since the latest bombings Wednesday, could not be reached for comment on the new fighting.

The Tamil Tigers have been fighting since 1983 to create a separate homeland for Sri Lanka's minority ethnic Tamils following decades of discrimination by governments controlled by the Sinhalese majority.

The group, branded a terror organization by the U.S. and European Union, is responsible for more than 240 homicide bombings as well as scores of other deadly attacks.