Mayors from near the Italian city of Naples have rejected a government proposal to indefinitely freeze the opening of a new regional waste dump.
The government had offered to postpone opening the new dump in Terzigno if area residents put an end to weeks of violent protests against it.
The mayors said they want the rubbish dump plan permanently abandoned.
Protesters have blockaded the existing dump and rubbish lies uncollected on the streets of Naples and nearby towns.
"We decided not to sign the document without additional guarantees that a second dump at Terzigno will not be opened, as requested by our people," said Gennaro Langella, the mayor of nearby Boscoreale.
The government's offer was put to the region's mayors by the head of Italy's civil protection authority, Guido Bertolaso.
Mr Bertolaso had been sent to Naples by Prime Minister Silvio Berlusconi in a bid to put an end to weeks of protest over the rubbish dump.
Six policemen were reportedly injured as hundreds of demonstrators clashed with police late on Saturday in Terzigno, near the proposed new dump at the foot of Mount Vesuvius inside a national park.
There was a further, peaceful, demonstration in Terzigno on Sunday.
Mr Bertolaso said he would go ahead with a plan to clean up Terzigno's existing landfill and continue to use it until it was full. A nearby incinerator and landfills elsewhere would also be used to dispose of rubbish from Naples.
Another meeting between Mr Bertolaso and the region's mayors was set for Tuesday.
Earlier in the week, police charged at protesters outside an existing dump in Terzigno after officers were injured as protesters set rubbish trucks alight and threw fireworks.
After an emergency meeting about the crisis on Friday, Mr Berlusconi promised on Friday to spend 14m euros (£12.5m) to upgrade the current Terzigno dump, saying the site did not pose a health risk.
Naples has suffered years of waste mismanagement fuelled by corruption and organised crime.
Residents fear contamination by unregulated and toxic waste disposal and successive governments have been unable to solve the problem.
The European environment commissioner has warned Italy faces legal action and heavy fines if it does not improve waste management in Naples.