A migrant boat has sunk off the Sicilian island of Lampedusa leaving at least 94 people dead, a coastguard official has told IBTimes UK.

Floriana Segreto also confirmed that the dead include a pregnant woman and two children.

Segreto told our reporter that 151 people had been rescued from the vessel after it sank off the tiny island. Witnesses claimed, however, that hundreds of migrants were still in the waters.

Local reports said that there are still 200 people unaccounted for.

The boat was believed to have been carrying about 500 people at the time.

Those rescued are sub-Saharan migrants, including Somalians, Eritreans and Ghanaians.

The boat was believed to have sunk after a fire broke out on board. According to survivors, the fire started when some refugees set fire to objects in an attempt to catch the attention of local fishermen off Lampedusa.

"The survivors are in a state of shock," the mayor of Lampedusa, Giusi Nicolini, said on news channel SkyTG24.

"They have been in the water since the early hours of the morning,"

"The first assistance was provided by people on pleasure boats who heard the screams," Antonino Candela, a local emergency medical worker, told Reuters.

Prime Minister Enrico Letta tweeted that it was "an immense tragedy".

"There is no miraculous solution to the migrant exodus issue," said Italian Foreign Minister Emma Bonino. "If there were we would have found it and put it into action."

The mayor of Lampedusa, Giusi Nicolini, described the scene as a "continuous horror".

Pope Francis sent a tweet calling for his followers to pray for the "victims of the tragic shipwreck off Lampedusa"

Lampedusa has become one of the main points of European entry for Syrian, Somali and Eritrean migrants. Since the beginning of the year, 6,000 Syrians have arrived on Italy's Sicilian coast.

The sinking off Lampedusa came just three days after 13 men drowned while trying to reach southern Sicily..

Immigrants in a dinghy near Lampedusa in 2012 (Reuters) Reuters