Warning: graphic images of injuries below

Refugee advocates have called on the Turnbull government to urgently address the alleged bashing of two Iranian asylum seekers by police and PNG immigration officials on Manus Island, with claims the pair were held for 36 hours without adequate medical attention.

Refugee Action Coalition spokesman Ian Rintoul said the two men, Mehdi and Mohammad, were taking part in New Year's Eve celebrations in the island's Lorengau settlement on Saturday when local immigration officials told them to return to the immigration detention centre, before the men were assaulted by officials and local police officers about 8pm.

Photos of their injuries show blood and bruising to their faces, necks and backs, including a large bruise across Mohammad's shoulders which appear to be the result of being struck with a long object.