To help support the economic recovery, the Fed buys $85bn in bonds every month, which pumps money into the financial system.

“We do have differing perspectives on the problem, but we share an interest in reducing the violence,” Obama said.

Most of the 48 on the list are from Yemen and Afghanistan. Two are now dead — one by suicide, the other by heart attack.

An explosion rocked an area in the west of the Afghan capital, Kabul, close to the country's national parliament, police said.

Saif al-Islam is currently being held in the western Libyan town of Zintan, following his capture by militiamen at the end of 2011.