Seven young people have been killed while walking to a lake with seven other friends, who managed to escape the brutal attack.
The group were heading to Gatun Lake, 80km north of Panama City in Panama, Central America, on Friday (local time) when they were set on.
Local media has reported that the group were planning to go swimming in the lake.
The bodies of the victims, four women and three men ranging in age from 17 to 22 years old, were found on Saturday, homicide prosecutor Adolfo Pineda told reporters.
The surviving group, who are assisting authorities with the investigation, said two men had attacked them.
“It really is a shocking occurrence from all points of view,” Mr Pineda said, adding the motive for the attack was also under investigation.
Local media reported that some of the victims' family members had reported them missing on Friday.
The public prosecutor's office said one person had since been arrested in relation to the incident.
Reports suggest five bodies were found inside a bunker on the lake shore, while the other two were found in the open air.
While autopsy results have yet to be released, TVN reported initial investigations suggested the deceased were the victims of torture and gunshot wounds.
Mr Pineda told the media the apparent “abuse of power” over the women were of particular concern.
Police, accompanied by survivors of the attack, have revisited the scene of the crime to map out how the incident unfolded, according to the network.
Gatun Lake is a scenic man-made lake that forms an important part of the Panama Canal.
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