Updated

Suspected Tamil Tiger rebels detonated a bomb hidden in a roadside flowerpot in Sri Lanka's capital Monday, killing one person and injuring six others, including four children who were on their way to school, authorities said.

The blast next to one of Colombo's main thoroughfares came amid months of increased fighting between the separatist guerrillas and government forces in the jungles of northern Sri Lanka.

In the latest fighting along the front lines separating government-held territory from the Tamil fighters' de facto state, government forces destroyed eight rebel bunkers in the Mannar area early Monday in a battle that killed 10 rebel fighters and three soldiers, said Brig. Udaya Nanayakkara, Sri Lanka's military spokesman.

Police also shot and killed two rebels in the eastern Amapara district, Nanayakkara said. A series of battles along the front lines Sunday also killed 11 rebels and five soldiers, the military said Monday.

Nanayakkara said the rebels, known formally as the Liberation Tigers of Tamil Eelam, are under increasing military pressure in the north and are attacking civilians in the south to try to distract the security forces.

"This is definitely the LTTE," he said of Monday's bombing. "They are desperate in facing the military in northern areas and they want to create some sort of fear psychology in people living in these areas."

Rebel spokesman Rasiah Ilanthirayan could not immediately be reached for comment, but the Tamil Tigers routinely deny carrying out such attacks.

Monday's attack took place as the government held local elections in the turbulent eastern city of Batticaloa, the first test of democracy in the region since the military seized the east from the rebels last year. Thousands of security officers were protecting polling places in that region to ensure a peaceful vote.

Although government forces have driven the rebels from the eastern province, some rebels who mingled with civilians attempt to carry out attacks targeting patrolling troops, according to the military.

The bomb in Colombo was hidden in a package that was either placed inside or atop one of several large concrete planters decorating the road divider in Wellawatta in southern Colombo, Nanayakkara said.

A man who went to inspect the package was killed in the blast, just before 7 a.m., and six others were injured, including four children, he said.

An Associated Press journalist at the scene saw a dead body on the street, a major north-south axis in the city. The army quickly closed the road. Cement and pieces of the flower pot were scattered along the road. The windows of office buildings more than 10 meters (30 feet) away were shattered.

T. Sunil, 47, a rickshaw driver, said he rushed to the bomb site and found a man on the ground with severe burns and a girl with bad injuries to both her legs. He took her to the hospital, where he saw several other injured students, he said.

Sri Lanka is embroiled in a quarter-century civil war with ethnic Tamil rebels that has killed at least 70,000 people. The Tamil Tiger rebels, listed as a terror group by the United States, European Union and India, have been accused of scores of bombings throughout the country.