Manhunt for the "White Widow": Mysterious woman with suspected links to terror cell

A manhunt is on tonight for a terrorist known as the White Widow and she is a mysterious woman who is believed to have ties to an east African terror cell with links to al-Qaeda.

According to officials, elusive militants that plan terrorist attacks both here in the U.S. and abroad are the biggest threat to America. The attack at the U.S. consulate in Libya is a stark reminder.

When we traveled to the Mali border in Africa, we witnessed first hand how intimidating and powerful these militant groups can be. CNN's David MacKenzie has traveled to Mombasa to unravel the mystery of the White Widow.