By Ranga Sirilal

COLOMBO, April 20 (Reuters) - Sri Lankan Tamil Tiger rebels said a Catholic priest and human rights activist has been killed in a roadside bomb attack they blamed on government forces while the military denied the claim.

The Liberation Tigers of Tamil Eelam (LTTE), who are fighting for an independent state in the north and east of the island, said Father M X Karunaratnam, who also heads the NorthEast Secretariat on Human Rights, died in Kilinochchi in the rebel-held island's far north.

"He was targeted by the (government's Deep Penetration Unit) DPU while he was returning to his residence after attending to mass at Mankulam parish," said rebel military spokesman Rasiah Ilanthiraiyan in a statement sent by e-mail. "He always spoke for the rights of the people of North East."

The military denied responsibility for the attack.

"That area is under LTTE control, We do not operate that deep in to LTTE control area. We can't take any responsibility," said Military Spokesman Brigadier Udaya Nanayakkara.

"Definitely it must be LTTE or some other fraction of the LTTE must have killed him."

The Sri Lankan military also said 10 Tamil Tiger rebels were killed in fighting in the far north on Saturday.

The government and rebels often make death toll claims that are nearly impossible to verify independently.

After driving the rebels from the east, government forces are focusing on Tiger-held areas in the north, intensifying fighting in a civil war that has killed an estimated 70,000 since 1983.

The rebels have hit back with bombings in Colombo and elsewhere in the relatively peaceful south of the island when they have come under military pressure in the past.

Nordic truce monitors, who blamed troops and rebels for repeated abuses, were banished by the government after President Mahinda Rajapaksa formally scrapped a 6-year truce in January, accusing the rebels of using it to regroup and re-arm.

Rajapaksa's government has pledged to destroy the Tigers militarily.

Analysts say the military has the upper hand in the latest phase of the war, given superior air power, strength of numbers and swathes of terrain captured in the island's east.

But they see no clear final winner and rebels still retain striking capability despite high security and military gains. (Editing by Sami Aboudi)

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