A Spanish tourist's visit to Rio de Janeiro's largest slum, Rocinha, proved fatal when she was shot and killed by the military police.

The incident took place at around 10:30 a.m., when the car she was riding drove past a police barrier and officers opened fire, according to a police statement.

Police later realized the car was ferrying tourists, including 67-year-old Maria Esperanza Jimenez Ruiz, who was shot in the neck.

Ruiz was rushed to a hospital, where she succumbed to her injuries. She suffered cardiac arrest, Associated Press news agency reported, citing authorities.

The Rio state security secretariat, which oversees all police forces, said the shooting would be investigated.

"This is unacceptable," said Fabio Cardoso, an inspector with the civil police force. "We are going to work to identify and jail the person who did this cowardly act against a Spanish tourist."

A druglord's den

The incident comes in the backdrop of a massive operation launched by the military police and Army soldiers in Rocinha against high-level drug traffickers. The slum, one of the largest in Brazil, has witnessed severe violence for a month between rival gangs fighting for control over the drug trade.

Two officers were reported injured in firefight between police officers and suspected drug traffickers in Rocinha early Monday, just hours before the killing of the Spanish tourist.

ap/kms (Reuters, AP, dpa)