It is estimated more than 24,000 people could have been infected with measles.

The three children who died were aged six months, four and 10.

There were 981 reported cases of measles in the Campania region of southern Italy between January and May this year.

In Campania, where the largest city is Naples, only 53% of children have been vaccinated against measles by the age of two.

Outbreak fears

In the UK, latest figures show 84% are immunised by that age, compared to 92% in 1995.

There have been 159 cases of measles so far this year, compared to the normal annual average of 100.

After an increase in the number of cases of measles in London this year, some doctors warned their could be an outbreak there within the next two years if parents continue to reject MMR.

Dr Marta Ciofi, an epidemiologist at the Istituto Superiore di Sanita in Rome told BBC News Online the area where the measles outbreak occurred had a history of very low vaccination uptake.

She said: "In Campania, the levels are very low and insufficient to interrupt measles transmission."

Dr Ciofi said coverage could be patchy because it was down to regional health authorities to offer and promote the MMR vaccine.

Some doctors are also concerned about its potential side effects.

The authorities have implemented a series of measures, including offering MMR to younger children and to older ones who have not been immunised, to try to halt the epidemic.

Dr Ciofi said: "I think we have paid a very high price, but this epidemic has been a strong lesson for all the physicians and parents."

She added: "We have missed the seriousness of measles when the incidence of the disease decreased. But this shows we can still have deaths from it in 2002."

'Not scaremongering'

Dr Natalie Crowcroft, a consultant epidemiologist at the UK's Public Health Laboratory Service, said the situation in Campania was no surprise to experts.

"If you have low vaccination coverage, measles eventually comes back.

"That's very sad for these children in Italy.

"Those affected have been of all ages."

Dr Crowcroft added: "We're not scaremongering.

"But the overwhelming message is that parents need to think about how to protect their children.

"And the message is that MMR is the best way to do that."

She said Italy also had more cases of mumps and rubella than the UK.