UPDATE 1-Gunfire heard in Sudanese capital- witness

Gunfire was heard on Tuesday at two buildings used by Sudan's general intelligence service in the capital Khartoum, two Reuters witnesses said.

Security forces blocked the road leading to one of the buildings, one witness said. The district is close to the capital's airport. No further information was immediately available.

Sudan is undergoing a three-year political transition overseen by civilians and the military following the overthrow of long-time ruler Omar al-Bashir in April.