More than 30 migrants, including a baby, have died and dozens more have survived after their overloaded boat sank in rough seas off southern Italy.

The vessel reportedly broke apart while trying to land with more than 100 people aboard near the coastal town of Crotone in the Calabria region.

Many bodies have been recovered from the beach at a nearby seaside resort.

Large numbers of people fleeing conflict and poverty make the crossing from Africa to Italy each year.

It is unclear where this boat had travelled from but the Adnkronos news agency reported that those aboard were from Iran, Afghanistan and Pakistan.

The vessel sank after it crashed against rocks during rough weather, the news agency said.

The death toll "has surpassed 30," Danilo Maida, spokesman for firefighters in Calabria, said. "Several dead are reported among the migrants, (and) about 40 survivors," the national firefighters' department wrote on the Telegram messaging app.

"There had been landings but never a tragedy like this," the mayor of Cruto, Antonio Ceraso, has told Rai News.

Italian Prime Minister Giorgia Meloni - elected last year partly on a pledge to stem the flow of migrants into Italy - expressed "deep sorrow" for the incident, blaming the deaths on traffickers.

"It is inhumane to exchange the lives of men, women and children for the price of the 'ticket' they paid in the false perspective of a safe journey," she said in a statement.

"The government is committed to preventing departures, and with them the unfolding of these tragedies, and will continue to do so."

According to monitoring groups, more than 20,000 people have died or gone missing at sea in the central Mediterranean since 2014. (BBC)