Colombo  - The death toll in Friday's bus bomb explosion rose to 26 as fighting continued in the northern part of the country claiming the lives of 18 more rebels, officials said Saturday.

At least 63 of the 70 injured in the blast at Piliyandala, 12 kilometres south of the capital, remained in hospital, while hospital authorities were releasing the bodies of the 26 killed to their relatives.

The police, which has blamed the rebels of the Liberation Tigers of Tamil Eelam (LTTE) for the blast, arrested nine people, all of them minority Tamils on suspicion that they were involved in planting the bomb.

However, there was no confirmation that the suspects had a hand in the bombing.

All passengers killed were from the majority Sinhala community and included a Buddhist monk.

Police believe that the bomb had been kept in the hood rack and a timing device had been set to the bomb.

The bus was leaving the main stand when the explosion went off during the evening rush hour.

Meanwhile at least 18 Tamil rebels were killed and similar numbers wounded when the infantry and armoured battalions moved during multi- pronged assaults launched in three different areas in the north on Friday, a military spokesman said.

The operations were launched in Mannar, Vavuniya and Welioya, more than 250 kilometres north of the capital.

In a separate development, troops have secured control of a venerated Catholic church, which was in a previously rebel-controlled area in Mannar.

Fighting between security forces and rebels has intensified during the past four months, with the military claiming to have killed more than 3,000 rebels while losing over 400 security personnel.

On Wednesday, troops came under attack from the rebels in Muhamalai, 390 kilometres north of the capital, and the military claimed to have killed over 100 rebels and said 43 soldiers died.

It said 33 others were missing in action, but other sources said over 185 soldiers were killed. (dpa)