Seven young people on a trip at Gatún Lake, which forms part of the Panama Canal, were found murdered in a wooded area near the lake Saturday, the BBC reports. All had been shot in the head. The victims, four males and three females aged 17 to 22, were part of a group of 13 who set out for a hike, the AP reports. The others escaped and told authorities they had been attacked by two armed men. One suspect, who is 18, has been arrested and charged with murder, but police say there may be others. The victims are said to include two teenage sisters. (More Panama stories.)