A group of 300 young migrants have reportedly 'barricaded' themselves inside a building in southern Italy to demand better living conditions.

The migrants piled up furniture and stopped people entering the refugee welcome building in Reggio Calabria for eight hours, according to local reports.

Police in riot gear are said to have attended the scene as well as officials from the Immigration Bureau in a bid to stem rising tensions.

The young migrants reportedly made a list of demands concerning their living conditions and some asked to be moved elsewhere, including the north of Italy and Germany.

In May, the Italian Navy ship 'Vega' arrived with more than 600 migrants and refugees on in the port of Reggio Calabria, southern Italy (file photo)

The refugee welcome centre inside the former Law School of the University of Mediterranean Studies currently houses 340 young people.

Reggio Calabria is an area where many migrants arrive in Italy by boat.

However, the number of people arriving in the country has changed in recent years.

According to the International Organisation for Migration, from 2014 to 2015, a major and sudden shift in routes of irregular migration by sea to Europe occurred.

About 853,000 migrants arrived in Greece in 2015, compared to 34,400 in 2014.

Almost 154,000 arrived in Italy in 2015, compared to 170,100 in 2014.

Women rescued at sea arrive aboard the Italian Navy ship 'Vega' on May 29 in the port of Reggio Calabria (file photo)

In May, the treacherous Mediterranean Sea crossing from Libya to Italy claimed the lives of at least 1,083 migrants in one week — mostly because barely seaworthy smuggling boats foundered and sank despite calm seas and sunny skies.

The staggering death toll foreshadowed more disasters as the region geared up for the traditional summer-fall spike in human trafficking as the weather improves and seas grow warmer.

Aid officials say it also suggests that Libyan smuggling gangs are using even riskier tactics to profit from the torrent of people desperate to reach the safety and economic promise of Europe.

Making matters worse, the tally is only from the capsizings or shipwrecks known to authorities, who acknowledge they don't have precise information on how many people are being jammed into unsuitable vessels and swallowed up by the vast waters of the southern Mediterranean.