A municipal policewoman was fatally shot Wednesday while trying to detain assailants who had just robbed a post office in the Spanish capital, authorities said.

Carmen Muñoz Garcia, 62, became the first female member of the Madrid police force - and the third nationwide - to die in the line of duty.

In their patrol car, Muñoz and 52-year-old partner Santiago Lozano intercepted a van traveling at high speed in the capital's Usera district, city councilor Paz Gonzalez said at the scene of the incident.

When the officers got out of their car, the occupants of the other vehicle, who were fleeing after the post office heist, "immediately began shooting indiscriminately," the councilwoman said.

Muñoz died from a bullet wound to the chest, while her partner survived and was taken to a hospital, Gonzalez said.

Witnesses told Efe they heard between three and five gunshots.

Two local policewoman in the southern city of Cordoba, Maria de los Angeles Garcia Garcia and Maria Soledad Muñoz Navarro, were killed on Dec. 18, 1996, by a bank robber armed with a machine gun.