EU member states must take up their responsibilities to help deal with the thousands of migrants pouring across the Mediterranean, the commissioner for migration said.

Dimitris Avramopoulos said that while the EU is developing the policies, the member states and their resources must implement them.

His comments come as some 10,000 migrants have been rescued making the perilous crossing to Europe in the past week, while hundreds of others are feared drowned.

"Europe is accomplishing its duty, it's up to the member states to implement it," he said, referring to a new EU policy to be presented in May.

He urged member states to show solidarity with those bearing the brunt of the arrivals.

Meanwhile, the UN refugee agency said at least 20 migrants rescued at sea by the Italian navy had suffered burn injuries, some of them grave, in a cooking gas explosion before departing Libya on a smuggler's boat.

The UN High Commissioner for Refugees said that none of the victims had been properly treated before boarding an inflatable dinghy for Italy, and at least one of the burn victims had died en route.

The 20 burn victims included a six-month-old child.

They were among 70 migrants, mostly refugees, who arrived on Friday on the island of Lampedusa.