Some of the dead are being stored in lorries

Other unclaimed victims whose identities are not known are being buried in unmarked paupers' graves.

Up to 10,000 people, many of them elderly, are believed to have died in France's extreme summer temperatures of more than 40C (104F).

A political row has been raging over who was to blame for the deaths, and over the government's perceived slow response to the crisis.

The French newspaper Le Figaro said 300-400 bodies were lying unclaimed in Paris alone.

Maybe they don't have relatives - a great-nephew or otherwise - who is interested in a burial Paris Mayor Bertrand Delanoe

More than 100 bodies of them are having to be stored in refrigerated lorries in the Paris suburb of Ivry-sur-Seine, it says.

And in a refrigerated hanger at Rungis being used as an overflow mortuary for the Paris region, around 100 of the 160 bodies brought in since 15 August remain unclaimed, the paper adds.

Paris Town Hall has appointed a team of people to track down their relatives, but Mayor Bertrand Delanoe has admitted that some of the victims may have died in complete isolation and their families may never be traced.

"Maybe they don't have relatives - a great-nephew or otherwise - who is interested in a burial," Mr Delanoe told the French news channel LCI.

Unclaimed victims are being buried in unmarked graves

"In any case, we're doing all that we can so it takes place in the most emotionally honourable conditions."

Paris authorities have extended from six to 10 days the legal time permitted between death and burial, to allow families extra time to claim their dead relatives.

Some government officials and newspaper have blamed family neglect for the high toll in the heatwave.

"It's not up to the Father State to take care of our elderly. It's up to us," wrote Figaro columnist Renaud Girard under a headline "French barbarity."

But government critics say health cuts and a slow response were central to the problem.

Chirac is promising health care changes

The French surgeon-general who resigned after government criticism said the deaths were probably unavoidable.

French President Jacques Chirac has promised changes to the country's health system.

"Everything will be done to correct the insufficiencies that we noted in our health system," he said in a live televised address to the nation last week.