BERLIN - Islamist militants are increasingly funding themselves through kidnapping, with al-Qaida's north African wing likely to have brought in tens of millions of dollars in ransoms in the past few years, a senior US Treasury official said.

The United States estimates militant organizations received $120 million in ransoms over the past decade, including to al-Qaida in the Islamic Maghreb (AQIM) in recent years, said David Cohen, undersecretary for terrorism and financial intelligence.

Kidnapping for ransom was an "urgent threat," particularly in the Sahel, a belt of land spanning nearly a dozen of the world's poorest nations on the Sahara's southern rim, Cohen told reporters in Berlin on Tuesday.

"It is what has become perhaps the most challenging and fastest growing technique that terrorist organizations, in particular the affiliates of al-Qaida in North Africa and in Yemen, have been using to fund themselves over the last couple of years."

Please LIKE our Facebook page - it makes us stronger