More than 300 migrants have been saved from rough waters in separate incidents off the coasts of Italy and Greece.
The Italian navy said it picked up 233 people, mostly from African countries, who had been stuck in an “overcrowded” vessel south of Sicily.
Meanwhile Greek coast guards rescued 85 migrants off the island of Astypalaia.
Every year thousands of African and Arab migrants fleeing war and poverty risk their lives trying to reach the Europe.
Greece and Italy are both main entry points for those who attempt to make the dangerous sea crossing.
In October more than 400 people drowned in two shipwrecks near the Italian island of Lampedusa.
Many of them were from Eritrea and Somalia, but the civil war in Syria has also resulted in an increased flow of migrants trying to reach Europe.
Italian officials said on Thursday that the migrants were rescued from a 10-metre-long (33ft) boat about 130km (80 miles) from Lampedusa.
“Considering the rough seas, the overcrowded boat and the precarious conditions, a situation of emergency was declared,” the Italian navy said in a statement.
It added that the migrants were in good health and had been ferried to Sicily.
They are reported to have come from Eritrea, Nigeria, Somalia, Zambia, Mali and Pakistan.
Greek authorities said they picked up migrants near Astypalaia after receiving a distress signal from the vessel’s captain because of bad weather.
Women and children were among those rescued.
In the past, human rights organisations, including the UN refugee agency UNHCR, have strongly criticised Italy and Greece countries for “push-backs” – a policy of sending migrants back to their point of departure.
In the aftermath of the Lampedusa shipwrecks, the Italian government launched an operation called “Mare Nostrum”, mobilising warships and aircraft to prevent further tragedies.
The country has also called for help from other EU states to deal with the migrant influx.
The European Commission has asked for more resources for joint sea patrols, and more co-ordination with countries that migrants embark from, such as Libya.