ROME, Dec. 2 Government officials here expressed fresh worries today about illegal immigrants trying to reach southern Italy from northern Africa, a perilous passage that led to the drowning over the weekend of at least a dozen immigrants who had left Libya by boat.

According to the Libyan news agency Jana, 12 people died, and 56 more were still missing today, after a shipping vessel carrying about 120 illegal immigrants sank in bad weather off the Libyan coast on Saturday. It was bound for Italy.

The immigrants are part of a growing problem that Italy has yet to figure out how to handle. Although a tough new anti-immigration law, enacted earlier this year, was meant to deter illegal immigrants from trying to enter the country, they continue to come, at extraordinary risk.

Every month, hundreds of desperate people set out in ill-equipped boats from Libya, Tunisia and other points in northern Africa, hoping to slip unnoticed into Italy, which has a coastline too long to be easily patrolled.

Almost every month, dozens or scores of them die when a boat goes down, or when they try to swim the final stretch to land.

"It can't be stopped," said Maurizio Fistarol, a member of Parliament, in an interview today. "It's like stopping a thunderstorm or the tides."

Other officials echoed his frustration, and they and Mr. Fistarol said that in order to prevent a continued loss of life, Italy needed to redouble its efforts to coax more cooperation from law enforcement officials in the countries from which the immigrants were leaving.

Alfredo Mantovano, under secretary of the interior, noted that agreements Italy had reached with Turkey and Albania, for example, had dramatically curtailed the tide of immigrants from those countries trying to reach Italy's southeastern coast.

Referring to that region, Mr. Mantovano said, "Illegal immigrants haven't disembarked in Puglia since the middle of August."

But the immigration route from northern Africa to Sicily and other southern and southwestern points in Italy has grown busier, and it appears to be an especially dangerous one, governed by traffickers with little regard for safety.

"In Libya, we're still in the first stages of talks," Mr. Mantovano said. "It's now the weak point in the Mediterranean."

Many of the immigrants are simply trying to use Italy as a portal into other European countries, and Mr. Fistarol and Mr. Mantovano complained that Italy needed more help from those countries.

"It would be more useful if, instead of Italy dealing with Libya, all of the European Union was," Mr. Mantovano said.

Mr. Fistarol said: "This isn't a phenomenon that one nation can stop on its own. It's a phenomenon of this epoch, and it takes all of Europe to face it."