Panama's National Police said Thursday that three of its officers are under investigation for a shooting incident that left a 2-year-old boy dead and a teenage girl badly wounded.

"We are waiting for scientific results on the various indicators, such as shell casings and bullets, which will be compared with the (officers') firearms," homicide division chief Rafael Santiago told a press conference.

The shooting occurred Wednesday at a police checkpoint on the Panamerican highway some 100 kilometers (60 miles) west of Panama City.

For reasons unknown, some officers at the checkpoint fired shots at a car carrying a couple from India and their two children.

The boy died, while his 15-year-old sister remains in serious condition at Santo Tomas Hospital in the capital.

Initial findings indicate the shots were fired by plainclothes officers, Santiago said, adding that no weapons were found inside the Indian family's car.

The internal police probe is being conducted in parallel with an investigation by the Attorney General's Office, National Police director Julio Molto said.

The checkpoint was set up based on an "alert involving an automobile with similar characteristics" to the one driven by the Indian family," Molto said. EFE