The EU and Italy have been told they must take urgent action to prevent more migrants dying at sea after the tragic sinking off the Italian island of Lampedusa this week.

Over a hundred African migrants died in the sinking, many of them believed to be fleeing desperate circumstances in their own countries.

The World Council of Churches (WCC) general secretary Rev Dr Olav Fykse Tveit expressed his "sadness, horror and concern" over the tragedy on Thursday.

"We mourn with their families and communities, and pray that God will comfort and sustain their loved ones. We hold the survivors, and all migrants forced to take these dangerous journeys, in our thoughts and prayers," he said.

Dr Tveit warned that political and economic instability was pushing people to make the dangerous journey and that opportunistic criminals were taking advantage of the situation.

He said there was the need for a "serious demonstration of a political will by those in power to put an end to the frequent occurrences of people dying at sea".

"Legitimate concerns over border controls by Italy and other European Union member states must never compromise the safety of those who, in desperation, take to the seas for refuge," he said.

Tveit added that the tragedy was a reminder of "the dramatic divisions between rich and poor in this world" and the need to address the root causes of migration.

Pope Francis earlier spoke of his "great sorrow" over the sinking and described it as "a disgrace".