Apparent suicide attack on Tunisian presidential guard bus kills 12

Police and ambulances are pictured near the scene of a bombing of a military bus in Tunis, Tunisia November 24, 2015. REUTERS/Anis Mili

TUNIS (Reuters) - A bomb exploded on a bus packed with Tunisian presidential guards in the capital Tunis on Tuesday, killing at least 12 people in an attack one source said was probably the work of a suicide bomber.

Ambulances rushed wounded from the scene and security forces closed off streets around Mohamed V Avenue, one of the main streets in Tunis, before the president declared a curfew in the city and imposed a state of emergency nationwide.