US presidential candidate Ben Carson cancels Nigeria, Africa trip over security threats

One-time runner-up Ben Carson, a retired neurosurgeon who has recently slipped somewhat in the polls, announced Thursday he was calling off a planned trip to Africa because of potential security risks.

Carson, 64, told reporters on Thursday, 'It's classified information so I'm just going to say it's too dangerous,' according to a pool reporter.

Carson had planned to visit Nigeria, Kenya and Zambia in late December, including a stop to visit two Siamese twins he famously separated in a surgery when he was a neurosurgeon.

A Carson campaign official said the cancellation of the trip was unrelated to his recent drop to fourth place in recent polls on the race.