British armed forces forcibly boarded and regained control of an oil tanker in the English Channel on the evening of 25 October following a suspected hijacking, according to the UK defense ministry.
The vessel, the Nave Andromeda, attracted attention after failing to dock as expected in Southampton on the south coast of England.
A spokesperson for Hampshire police said that seven men were arrested "on suspicion of seizing or exercising control of a ship by use of threats or force."
"They all remain in custody at police stations across Hampshire," the statement added. "Investigators are speaking to the crew members to establish the exact circumstances of what happened."
During the altercation, several stowaways made verbal threats to the crew on board the tanker, Hampshire police told CNN earlier.
The crew members on the vessel are safe and did not sustain any injuries, Navios Tanker Management, the ship's operator, said in a statement.