Rio de Janeiro (AFP) - Brazilian police looking for criminals ended up targets of a sting themselves when a swarm of bees attacked, sending seven officers to the hospital.

The officers were searching a piece of forest by a farm in Resende, northwest of Rio de Janeiro, on Friday when "they found a box," the state police force said in a statement Saturday.

"On opening it, they encountered a swarm of bees and were attacked."

Seven officers required hospitalization, two of them being quickly released, the statement said. Of the five still in hospital, one was in intensive care.

Globo News television reported that one of the victims was stung 300 times.