ROME • Italy's coast guard has successfully coordinated the rescue of about 3,000 migrants in the Mediterranean after receiving distress calls from more than 20 overcrowded vessels drifting in the waters off Libya.

One of the biggest single-day rescue operations to date appeared to have been concluded without any reports of casualties.

Two navy ships, the Cigala Fulgosi and the Vega, picked up more than 900 migrants from two wooden boats in danger of sinking just off Libya last Saturday.

The coast guard said its patrol boats had taken on board a total of just under 1,000 people from various unseaworthy fishing boats and inflatables that had left Libya overnight last Friday.

Another 1,000 rescued migrants and refugees were reported to be headed for Italian ports on other boats as the wave of new arrivals triggered increasingly virulent attacks on centre-left Italian Prime Minister Matteo Renzi's handling of the migration crisis.

"This must be a joke. We are using our own forces to do the people smugglers' business for them and ensure we are invaded," said Senator Maurizio Gasparri from former prime minister Silvio Berlusconi's centre-right Forza Italia party.

Just over 170,000 migrants and refugees from Africa, the Middle East and South Asia landed at Italy's southern ports last year after being rescued in the Mediterranean, while the total for this year has already topped 104,000.

Humanitarian organisations say the surge in the number of people trying to reach European Union countries is the result of conflicts or repression in Africa and the Middle East.

They have called on European governments to shoulder more of the burden of absorbing the wave of asylum seekers and to help create safer routes for them to reach Europe.

AGENCE FRANCE-PRESSE