LONDON (AP) — Police have charged four men who were accused of threatening the crew of a cargo ship in the Thames Estuary outside of London.

Essex Police said Sunday the four were charged with “affray,” a crime defined as using of threatening to use violence in a way that makes by-standers fear for their safety.

The operator of the cargo ship Grande Tema said the men had been discovered stowed away on the vessel, which traveled from Nigeria to England.

The men were confined to a cabin but escaped and, according to ship operator Grimaldi Lines, threatened the crew with iron bars. Friday’s incident ended peacefully after authorities intervened.

The men range in age from 20 to 27.

They are scheduled to appear at Chelmsford Magistrates’ Court on Monday.