Sri Lanka's parliament Wednesday passed legislation to pay compensation to victims of the island's brutal civil war, nearly a decade after the end of the conflict which claimed 100,000 lives.

The legislature voted 59 43 to approve a broad reparations bill which seeks to establish an independent office that will compensate survivors as well as victims' next of kin.

Former strongman president Mahinda Rajapakse's followers voted against the bill, arguing that it amounted to compensating separatist Tamil rebels who were crushed in a no-holds-barred military campaign in May 2009.

The long-delayed legislation had been a key demand of international observers urging reconciliation in the island nation where divisions between minority Tamils and majority Sinhalese persist.

The office will decide on potentially tens of thousands of compensation claims from those afflicted by fighting that ended in 2009 with the defeat of the Tamil Tiger rebels.

President Maithripala Sirisena has faced international criticism for the lack of progress towards reconciliation since his election three years ago.

The United Nations Human Rights Council has led a chorus pressing Sirisena and his administration to take urgent steps towards addressing war-era abuses, including punishing soldiers and rebels accused of atrocities.

After years of delay, the government bowed to international pressure in March and established an office to trace the tens of thousands still missing since the end of the war.

Sirisena's pledge upon election in January 2015 to investigate the war and compensate its victims saw Sri Lanka narrowly avoid being slapped with international sanctions.

The previous Rajapakse regime, which ruled with an iron fist, refused to even acknowledge war-era abuses.

Sri Lankan forces were accused of killing up to 40,000 Tamil civilians during the final months of the war when the Tigers' quest for independence came to a bloody end.

International rights groups have called for the prosecution of both the military and the Tigers, who were notorious for suicide bombings and enlisting child soldiers.

Sirisena has expressed willingness to investigate specific allegations of wrongdoing but has ruled out allowing foreign involvement in any inquiry.