(Adds fresh fighting)

COLOMBO, Jan 30 (Reuters) - Sri Lankan air force fighter jets pounded northern rebel positions on Wednesday as ground troops attacked 35 rebel bunkers, killing at least 10 Tamil Tigers, the military said.

The clashes in the Jaffna peninsula came as the Liberation Tigers of Tamil Eelam (LTTE) blamed the army for a roadside bomb that killed 17 people, most of them children, on a school bus on Tuesday. The army denied the report.

Sea, land and air battles between government soldiers and the rebels, fighting for an independent state for minority Tamils, have escalated since a six-year truce was scrapped on Jan. 16.

"The troops attacked about 35 of the LTTE terrorist bunkers in Killali and Nagerkovil in Jaffna today in the early hours, destroying about 20," said military spokesman Brigadier Udaya Nanayakkara.

"Monitoring confirmed 10 terrorists were killed," he said, adding seven soldiers were wounded.

The Tigers said they beat back a military attempt to attack their forward defence line in Jaffna.

"Fighting units of the Sri Lankan Armed Forces (SLAF) backed by heavy artillery and mortar fire advanced towards LTTE position," said Tamil Tiger spokesman Rasiah Ilanthiraiyan in an e-mailed statement.

"In the end of the clashes that lasted about an hour, the SLAF fighting units that participated in the attempt fell back to their own fortified localities with casualties."

The fighting came a day after the Tigers blamed the military for a blast in the northwestern district of Mannar that killed 17 people, including 11 children and two teachers.

In a statement on their official Web site, the rebels said 17 others were wounded in the blast.

Military spokesman Nanayakkara denied the allegations, saying they were "fabricated stories".

There were no independent accounts of the clashes.

Analysts say both sides tend to overstate enemy losses and play down their own. The two-decade conflict has killed an estimated 70,000 people.

The majority-Sinhalese government has vowed to wipe out the Tigers militarily. Earlier this month it scrapped the ceasefire, saying the Tigers had used it to regroup and rearm.

Nordic truce monitors, asked to leave Sri Lanka by the government, say both sides repeatedly violated the ceasefire. (Reporting By Ranga Sirilal; Editing by Katie Nguyen)

AlertNet news is provided by