Three boats carrying more than 500 clandestine migrants arrived on the Italian island of Lampedusa today, triggering angry protests by residents who blocked a shipment of tents by ferry, reports said.

The latest arrivals took the total number of immigrants on the tiny island between Sicily and Tunisia to 4,000 while its reception centre has only been laid out for 800.

"The government does not respect the people and seriously endangers the citizens of Lampedusa," ANSA news agency quoted Lampedusa Mayor Dino De Rubeis as saying. "There is a risk of clashes with the security forces."

De Rubeis slammed the attitude of the centre-right government of Prime Minister Silvio Berlusconi in the longstanding refugee crisis as "disgraceful".

"Italy accepts that thousands of immigrants are treated like animals and forced to sleep in the rain, all of Italy should be ashamed," he said.

The Red Cross meanwhile said conditions in the reception centre were "unacceptable".