Rome  - An Italian coastguard vessel on Tuesday took on board 57 would-be immigrants who were found floating in a rubber dinghy some 10 nautical miles south of the Mediterranean islet of Lampedusa.

One of the rescued was immediately taken to Lampedusa to be treated for dehydration, the ANSA news agency said, citing officials.

The rest of the group, including four women, were expected to arrive in Porto Empedocle, Sicily later in the day.

The operation came just a few days after an incident in which dozens of migrants are believed to have died at sea. The incident has triggered a political row in Italy over policies implemented against illegal immigratrion by Prime Minister Silvio Berlusconi's government.

There are also concerns about cooperation between the Italian government and Libya on the matter.

Also on Tuesday, Interior Minister Franco Frattini, in a state radio interview, reiterated a call for the European Union to "do more," to counter illegal immigration. He also defended the Italian government's policies, including plans for Berlusconi to visit Libya on August 30.

Frattini has repeatedly said that Mediterranean EU members should not be left alone to bear the burden of illegal arrivals from the shores of North Africa. He has defended Italy's controversial agreement with Libya aimed at deporting migrants found in international waters.

Last week five Eritreans who were rescued by an Italian coastguard patrol claimed that some 73 of their fellow travellers died at sea in the 20 days since their rubber dinghy left Libya.

The sighting of at least eight bodies floating in Libyan waters by patrols of the EU border agency appeared to give some credibility to the Eritreans' claims.

However, Maltese officials said that when one of their patrol boats intercepted the five Eritreans earlier in the week, they were found in good health and turned down a rescue offer, saying they wanted to reach Italy.

Italy and Malta have reported a drastic reduction in the number of would-be immigrants landing on their shores from Africa following the coming into effect earlier this year of the Rome-Tripoli pact.

Under the agreement, Libya has committed to stepping up patrols along its shoreline, which is often used by the mostly African migrants as a springboard to reach Europe.

Italy also began deporting to Libya would-be immigrants intercepted in international waters.

United Nations officials, rights activists and the Vatican have criticized the Italian-Libyan accord, saying it violates the rights of political refugees trying to seek asylum.