"There is a risk of a real humanitarian emergency," Interior Minister Roberto Maroni said. The uprisings in Egypt and Tunisia are leading to a "mass flight" to Italian shores by undocumented immigrants, Maroni said.
Maroni said Italy needed European help and had made a request for the EU's justice and home affairs council later this month to discuss "the crisis in North Africa and its effects on immigration and internal security in Europe."
The next justice and home affairs council meeting is set for February 24-25.
Meanwhile a spokesman for Italy's coast guard in Lampedusa, a tiny island between Sicily and Tunisia's shores, told AFP that a total of 641 undocumented immigrants had been intercepted by coast guards since late on Thursday.
"They all said they were from Tunisia," the spokesman said.
The latest boat, carrying 181 people including 16 minors, was found early on Friday in Italian waters and taken to Lampedusa by coast guards.
They will undergo health checks and will then be taken to immigrant detention centres ahead of eventual repatriation, he added.
ANSA news agency also quoted officials at the Sicilian port of Trapani saying that coast guards had rescued nine Tunisian immigrants from a sinking boat on Friday near the island of Favignana.
"The problem is that the bilateral agreement that we have with Tunisia and which allowed up until now for an efficient management of illegal immigration is not being implemented because of the crisis situation," Maroni said.
Foreign Minister Franco Frattini said: "We are faced with a real immigration emergency and we cannot conceive that Italy should be the place where everyone arrives and everyone stays. We had an excellent collaboration with Tunisia."
Frattini said Tunisian Foreign Minister Ahmed Abderraouf Ounais will visit Italy next week "to re-confirm the cooperation agreements." The Italian foreign ministry website said the visit was expected next Thursday.
Giuseppe Lumia, a senator from the opposition centre-left Democratic Party, criticised the government for failing to prepare for the immigration flux.
"There is a real immigration emergency... The situation risks exploding any moment and the government is completely unprepared," he said.