Rome (AFP) - An Eritrean dubbed "the general", suspected of controlling a migrant trafficking network responsible for shipping thousands of people to Europe and sending some to a watery grave, has been extradited to Italy.

Medhanie Yehdego Mered, 35, who had been on a wanted list since 2015 for international people smuggling, was arrested in the Sudanese capital Khartoum and flown to Italy late Monday.

He is "the accused ringleader of one of the four largest criminal migrant trafficking organisations", the Sudanese interior ministry said in a joint statement with the country's British and Italian embassies.

Referred to in wiretapped conversations between his subordinate traffickers as "the general" for his control over a large area and number of "troops", Mered is accused of organising the smuggling of up to 8,000 people a year on migrant boats.

Investigators believe his organisation was responsible for packing migrants onto a boat that sank in 2013 off the Italian island of Lampedusa, claiming at least 360 lives in one of the worst disasters in the Mediterranean.

His arrest is "a key turning point in the fight against people trafficking," prosecutor Francesco Lo Voi told a press conference, while Italian Interior Minister Angelino Alfano dubbed it "an extraordinary result" in a bid to stop "merchants of death".

- 'Disregard for lives' -

It is the first time a suspected top smuggler has been arrested in Africa and brought to face justice in Italy, which has been overwhelmed by the arrival of hundreds of thousands of people since the migrant crisis began in 2008.

Mered allegedly directed operations in Africa but also kept fellow operators in Italy up to date on the arrival of boats, so migrants could be picked up and squeezed for more money to continue to their final destinations in Europe.

Between 2012 and his capture, he also played a key role in helping migrants escape from Libyan jails and detention centres, bribing guards to let them out and then holding them to extort money from their relatives back home, police said.

Mered was tracked down by the Sudanese intelligence services, with support from Italy's organised crime police and Britain's National Crime Agency.

A top Sudanese police officer told AFP on condition of anonymity that Mered was "accused of smuggling youngsters from Ethiopia, Eritrea, Somalia and Sudan across the Mediterranean through Sudan or Libya or Egypt".

Wiretaps of Mered's conversations revealed he was in contact with traffickers in northern Europe, particularly in the Netherlands and Scandinavia, and held a "senior position in a criminal network operating in several continents", Italian police said.

The taps followed smugglers who were constantly on the move between Eritrea, Ethiopia, Libya, Sudan, the UAE and Europe.

Mered was a contact point for people worried their loved ones may have disappeared during the perilous Mediterranean crossing but showed "disregard for the lives of the migrants, appearing cynical and unscrupulous".

There have been numerous reports from survivors of people being forced to board boats and dinghies on Libyan beaches at gunpoint, as well as reports of people being shot dead if they refuse or try to escape.

According to the UN's refugee agency (UNHCR), over 48,500 people have arrived in Italy by boat so far this year. More than 10,000 people have died crossing the Mediterranean to Europe since 2014.

On Wednesday, rescuers were hard at work off Libya, pulling at least 800 people to safety.

Doctors Without Borders, which picked up 226 people, quoted on Twitter a survivor who said "we're happy to be alive but our brothers are still in Libya".

"Last night they were beating us with iron sticks".