By Red Harrison BBC correspondent in Sydney

More than 30 men have been refusing food since before Christmas, hoping to persuade Australia to let them in.

Nauru Finance Minister Kinza Clodumar said Australia was failing to provide adequate medical care for them.

Australian Immigration Minister Amanda Vanstone said the men were free to eat and go home whenever they wanted to.

Nearly 300 people, mostly from Afghanistan, are being held on Nauru while their claims for asylum are processed under a plan to keep unwanted boat people out of mainland Australia.

Some of those on hunger strike have sewn their lips together. Some can no longer walk and at least six are reported to be seriously ill.

Ms Vanstone says this is not Australia's problem.

Mr Clodumar condemned her comments, saying Australia was ignoring a signed agreement to provide adequate medical care and must act immediately to recognise its obligations.

Doctors at the island's only hospital say the hunger strikers are stretching resources.

Ms Vanstone says the island's medical facilities are more than adequate and there has been no request for help.