ROME: A video shot over the weekend on the southern coast of Sicily shows some 50 North African migrants who have been expelled from Italy instead joining Europe's army of irregular migrants as authorities look on.

After more than 600,000 migrant arrivals by boat in Italy in the past four years, immigration has become a hot-button issue ahead of the March 4 national election. Polls show it to be one of the top concerns among Italians.

The video was immediately picked up by evening news programmes, with a story also appearing in the country's most-read newspaper, Corriere della Sera, on Monday.

Some of those in the video had been involved in scuffles on Friday at the migrant identification centre on the small island of Lampedusa, the news reports said.

On Saturday, the migrants were put on a ferry bound for Porto Empedocle on the Sicilian coast. Upon arrival, asylum seekers were bussed to shelters, while those not seeking asylum were given an expulsion order requiring them to leave the country within seven days, and then sent on their way.

While the procedure is in line with Italian law, it has rarely been documented. Unable and unwilling to return home, most migrants simply ignore the expulsion order and move on toward their destination, often in Northern Europe.

"It's not right that they abandon them to their fate without any help at all," Claudio Lombardo, a local activist who shot the video, told Reuters.

"They had to ask me where the train station was."

In the video, the migrants are seen carrying their expulsion order in one hand as they are handed a packed lunch. Then police watch them as they set off walking down a busy road.

They trudged the 15 km (9 miles) to the nearest train station, where they slept rough and then boarded a train for Palermo, Sicily's capital, in the morning, Lombardo said. From Palermo, they can find transportation further north.

Almost a half million irregular migrants are estimated to be living in Italy, while in 2016, almost a million irregular migrants were found to be living illegally in the European Union. The actual number is likely to be much higher since irregular migrants seek to avoid being identified.

Italian political leaders of all stripes say that irregular migrants should be immediately sent back home, but this is difficult to put into practice. That means often they are ordered to leave the country, but are not physically deported.