Five Navy seamen who were training at a military base in San Antonio, Tex., are facing charges of aggravated sexual assault in connection with an alleged rape one year ago at a park about an hour from the base.

The sailors, who were attending the Naval Technical Training Center at Lackland Air Force Base in San Antonio at the time of the alleged crime, were arrested on Friday at the base, according to local authorities.

Bail for the men — Mauricio Chaparro, 28, Kenneth Johnson, 20, Anthony Cooney, 21, Dominick Burns, 20, and Kyle Tuschmann, 19 — was set at $500,000 for each, and all five are being held at Hays County Jail in San Marcos, Tex., according to local officials.

Details on the allegations are thin. But according to a police report, shortly after 10 p.m. on May 19, 2018, an officer with the San Marcos Police Department responded to a report that six people were involved in a sexual assault in the back of a truck in Rio Vista Park, a city-run park with tennis courts and hiking trails along a river.