Ben Carson
Ben CarsonReuters

Republican presidential candidate Ben Carson cancelled a scheduled trip to Israel, Kenya, Zambia, and Nigeria, he announced late Thursday night, citing security concerns. 

Carson's senior advisers noted that there were "active, credible" threats made against Carson from the Islamist terror group Boko Haram in Africa.

He did not mention specifics about why his Israel trip was canceled, however, and implied that the move may have been due to the costs of scheduling two separate trips at different times. The Israel-Africa tour had been scheduled to begin on December 27. 

"It's classified information so I'm just going to say it's too dangerous," Carson told a press briefing in Iowa.

He brushed off questions about whether it would hurt his credentials on foreign policy, as well, saying that "I think it'll make me look smart to not go into some place where there's a lot of danger."

Carson is the second Republican candidate to cancel a scheduled Israel trip.

Last week, frontrunner Donald Trump said he would postpone his trip to Israel and reschedule his meeting with Prime Minister Binyamin Netanyahu planned for December 28 - a move widely seen as a consequence of controversial statements he made calling to ban Muslim immigration to the US.