An increasing number of illegal immigrants smuggled by boat to Italy are children sent by their families in Africa, the International Organization for Migration said Monday.

"Irregular migration is getting younger and younger," said Simona Moscarelli, IOM operations and legal officer on the tiny Italian island of Lampedusa.

Last year some 2,000 minors — many of them unaccompanied by adults — arrived in rickety boats in Lampedusa and Sicily, hoping to sneak into Europe and start a better life or fleeing from violence and persecution on the African continent.

But they run a great risk of being exploited by drug and sex traffickers, said Peter Schatzer, IOM's regional representative for the Mediterranean region.

Schatzer said he didn't have comparative figures of minors arriving in previous years, but that international workers had noted that the numbers were increasing dramatically.

All together, 16,700 immigrants arrived by boat in Lampedusa and the coast of Sicily last year, Schatzer said.

Many of them came from Nigeria, Morocco, Somalia, Tunisia, Eritrea, Ghana, and other African countries, and usually take a boat to Lampedusa from Libya.

Unaccompanied minors cannot be expelled, according to Italian legislation, Moscarelli told reporters in Geneva, where IOM is based.

Schatzer said more than 7,000 minors are currently in the care of Italian authorities.

"More and more minors either go on their own or are sent by their families for various reasons," he told reporters.

He said some families want to give their children a better life and others hope to establish a foothold in Europe so that other members can follow or have the children send money home.

Moscarelli said hopes are generally high among the young immigrants because generally several families collected the money to pay for the smuggling fee of between euro1,000 and euro1,500 (between US$1,600 and US$2,400) from Libya to Italy.

"There are four, five families that just invest the money for one, and that one has to bring the money back in one way or another," she said.

After a few days on the island, where they get food, shelter and legal assistance from IOM, the U.N. refugee agency or the Red Cross, Italian authorities transfer immigrants under 18 to small housing centers in Sicily, Moscarelli said.

Schatzer said Italy spends more than euro200 million (US$320 million) a year to enable the immigrant children to go to school and get basic services. A legal guardian is assigned to them, but some still can be abused — often by their fellow nationals.

"There are very often dramatic situations," he added.

He said the children's home countries should be more cooperative in taking minors back.