(CNN) -- Two American tourists and their guide were kidnapped Friday in the Sinai region of Egypt, authorities said.
Bedouin kidnappers want authorities to release a relative who is in detention in Alexandria on drug charges, said Gen. Ahmed Bakr, head of security in the North Sinai.
Kidnappings and armed robberies have increased since a popular uprising ousted Egypt's long-ruling dictator, Hosni Mubarak, last year.
In February, two American tourists were kidnapped and soon released in the Sinai region. The same thing happened in June, when two American tourists were released about a day after being abducted.
In the most recent incident, Bedouins stopped a tour bus en route to Taba and kidnapped the two tourists -- a man and a woman -- and their guide, Bakr said.
Authorities were trying to negotiate with the kidnappers, he said.