Italy’s navy has rescued more than 4,000 migrants from overcrowded boats in the Mediterranean Sea south of Sicily in the past four days and several other rescue operations are still going on, officials said yesterday.

This week’s warm spring weather has brought calm seas and a surge in new arrivals. Most migrants pay more than $1,000 to criminal gangs in increasingly chaotic Libya to make the crossing to Italy and the European Union.

Two suspected people smugglers were taken into police custody when the amphibious assault ship San Giusto and another Italian naval vessel arrived in the Sicilian port of Augusta near Syracuse yesterday with more than 1,500 migrants rescued at sea.

Rescue operations have been reinforced from five to eight ships

While on patrol, the San Giusto picked up one dead refugee and rescued two in critical condition.

“The rescue operations have been reinforced from five to eight ships and all are operating in the area of interest,” between Sicily and Libya, Captain Mario Mattesi said.

“The dead man and the two others all showed signs of probable carbon dioxide poisoning and burns from the petrol that was aboard the raft. One of the men was resuscitated on the San Giusto after being rescued,” he added.

The Geneva-based International Organisation for Migration said the arrivals were set to intensify.

“Our feeling and understanding is that there will be more movement because of instability in Libya, more movement of people coming up,” spokeswoman Christiane Berthiaume told reporters yesterday.

Italy is a major gateway into Europe for migrants arriving by sea from North Africa and sea arrivals more than tripled in 2013 from the previous year, fuelled by Syria’s civil war and strife in the Horn of Africa.

In October, at least 366 Eritreans drowned in a shipwreck near the shore of the Italian island of Lampedusa.