The oil tanker Nave Andromeda off the coast of England on Sunday, October 25, before British armed forces regained control of the ship.
London CNN  — 

British armed forces forcibly boarded and regained control of an oil tanker in the English Channel on Sunday evening following a suspected hijacking, according to the UK defense ministry.

The vessel, the Nave Andromeda, attracted attention on Sunday after failing to dock as expected in Southampton on the south coast of England at 10:30 a.m. GMT (6:30 a.m. ET) Sunday morning.

A spokesperson for Hampshire police said Monday 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.

“Concerns were raised to police for the welfare of crew on board the Nave Andromeda” on Sunday at 10:04 a.m. GMT (6:04 a.m. ET), Jack Backwell, a police spokesman, said in an email to CNN.

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 Monday.

The 750-foot (228-meter) vessel is registered in Liberia, according to PA Media. The tanker was south of the island when the incident occurred.

Two coast guard helicopters were sighted circling around the vessel on Sunday, according to Isle of Wight Radio, which also reported that a three-mile exclusion zone was placed around the area south of Sandown on the island’s east coast.

According to marine traffic data, the tanker departed from Lagos, Nigeria, on October 6.

Instead, the vessel made several zig-zag maneuvers just off the Isle of Wight within a few hours.

Bob Sanguinetti, chief executive of the UK Chamber of Shipping, told Sky News that the zig-zagging “could well have been a way of alerting the authorities.” The vessel would also have been in touch with authorities via radio, though, he said.

He said “the uncertainty here is over the motives of the stowaways and, like I said, it could be nothing more sinister than seeking political asylum.”

CNN’s Nina Avramova, Sarah Dean and Jonny Hallam contributed to this report.