Three escaped prison inmates may have killed two people, believed to be American citizens, on a yacht they are thought to have hijacked as they tried to make their way from Grenada to St. Vincent and the Grenadines, according to Grenada police.

Police in the small Caribbean nation said Thursday that preliminary information suggests that after escaping, the three escaped male prisoners hijacked a yacht in St. George, Grenada.

Police are currently working on leads that suggest that the two occupants of the yacht may have been killed in the process, the statement added. It is believed that the occupants of the yacht were American citizens.

The three suspects are now back in custody after their February 18 escape, police said. It is unclear how they were caught.

The Royal Grenada Police Force said three men - Ron Mitchell, 30, Trevon Robertson, 19, and Anita Stanislaus - had been charged on suspicion of robbery with violence. It added that Mitchell faces other charges including rape, indecent assault and causing harm.

Police said the men had been at the South St George Police Station before escaping custody on Sunday. They were recaptured on Wednesday.

CNN has contacted both Grenada and St. Vincent and the Grenadines police for more information related to this case.

We are aware of these reports involving US citizens. We are monitoring the situation and seeking additional information, a US State Department spokesperson told CNN Friday. US authorities are working with local law enforcement officials on the incident, the spokesperson added. (CNN)