Italy wants NATO to help defend its southern shores from an influx of migrants, Interior Minister Matteo Salvini has said.

The move signals that the country’s new government is set to take a much tougher line on immigration controls.

Mr Salvini, who heads the far-right League, also said that neighbouring Malta had to do more to help deal with would-be asylum seekers from Africa and warned that human rights groups looking to save migrants at sea would come under much greater scrutiny.

His anti-immigrant stance has resonated with Italians and the League emerged as the second largest force in parliament at elections in March.

The party has since joined up with the anti-establishment 5-Star Movement to form a government.

"I am in favour of NATO, but we are under attack. We will ask NATO to defend us. There are many concerns about terrorist infiltrations," Mr Salvini told reporters after meeting two bus drivers in the northern town of Como who say they were beaten by four asylum-seekers this week after asking to see their tickets.

"Italy is under attack from the south, not from the east," he added, referring to NATO's traditional focus on Russia.

NATO's Secretary General Jens Stoltenberg is due to visit Rome next week. It is not clear if the government planned to present a formal request for help.

More than 600,000 migrants have reached Italy by boat from Africa in the past five years, but numbers have dropped sharply in recent months.

New arrivals are down 85% this year thanks to deals struck by the previous government to keep foreigners from leaving the shores of Libya - a main departure point for migrants seeking a better life in Europe.

The role of charities in migrant rescue missions

Italy coordinates rescue missions in the Mediterranean, while the European Union border agency Frontex runs an anti-smuggling operation at some distance from the Libyan coast.

Charities operating boats in the area have played an increasingly important role in rescuing migrants who often travel in flimsy inflatable boats not designed for the open sea.

The United Nations estimates that at least 500 people have died in 2018 trying to cross the central Mediterranean, following some 2,853 fatalities last year.

Mr Salvini said the charity boats were "acting like taxis", adding: "We are working on this NGO front. Some are doing volunteer work, others are doing business."

A number of humanitarian groups suspended operations in the Mediterranean last year, accusing the previous centre-left government of hampering their operations.

Sea Watch, one of the few groups still sailing off Libya, said there was an "acute shortage" of rescue boats in the area.

It said this meant it had to stay at sea for three days with 232 refugees aboard because there was no-one else on hand to prevent further migrant tragedies.

In a statement, the group also said Malta had refused to take in the migrants and that as a result, the boat had to make the much longer journey to Italy to bring the people to land.

Even though the tiny island state of Malta is closer to Africa than Italy, it has largely left to Rome the job of coordinating sea rescues. Mr Salvini said this had to end.

"It is not possible for Malta to say 'no' to every request for help. The Good Lord put Malta closer than Sicily to Africa," he said.

Malta said it adhered to all its obligations regarding immigration and rejected the Sea Watch criticism.

"Malta will continue to respect these conventions with respect to the safety of life at sea, as happened in this latest case and indeed in each case," the government said in a statement.

Earlier this week Mr Salvini angered Tunisia by accusing the North African nation of sending its "convicts" to Italy under the guise of migrants.