An elite military unit has stormed a crude oil tanker near the Isle of Wight and detained seven people, following reports that stowaways had attempted a hijacking.
The incident occurred on the Liberian-registered Nave Andromeda, which was due to dock in Southampton earlier on Sunday.
Hampshire Police said it received warnings at around 10am that stowaways onboard a ship south of the island had made “verbal threats” to its crew.
The Ministry of Defence confirmed shortly after 8pm that armed forces had boarded the vessel and detained seven people.
“In response to a police request, the defence secretary and home secretary authorised Armed Forces personnel to board a ship in the English Channel to safeguard life and secure a ship that was subject to suspected hijacking,” the MoD said in a statement.
“Armed forces have gained control of the ship and seven individuals have been detained. Police investigations will now continue. Initial reports confirm the crew are safe and well.”
Home secretary Priti Patel responded by tweeting: “Tonight we are thankful for the quick and decisive action of our police and armed forces who were able to bring this situation under control, guaranteeing the safety of all those on board.”
The defence secretary Ben Wallace said: "I commend the hard work of the Armed Forces and police to protect lives and secure the ship. In dark skies, and worsening weather, we should all be grateful for our brave personnel. People are safe tonight thanks to their efforts.”
Richard Meade, editor of the shipping intelligence website Lloyd's List, said the seven stowaways were believed to have boarded in Nigeria.
"They were discovered by the crew and while they were trying to detain them in a cabin they got violent," he told The Independent.
"Officials assume the stowaways boarded the vessel in Nigeria."
Mr Meade said the Nave Andromeda had not called at a port on its voyage and that boarding at sea would have been "nigh-on impossible".
He added that stowaways were a common occurrence in Nigeria and that it was unlikely that those on board the ship intended to come to the UK.
The tanker's destination would not have been openly advertised in Lagos, he said, and it could deviate off route at any point.
"It is most likely a coincidence that the incident happened when they were discovered off the coast of the UK," Mr Meade added.
It was not treated as a counter-terrorism incident, The Independent understands.
The Nave Andromeda had set out on a voyage from Lagos, in Nigeria, to Southampton on 6 October.
Online tracking website Marine Traffic displays its planned arrival time as 10.30am on Sunday, but showed the ship almost stationary in the English Channel.
It remained off the southeast coast of the Isle of Wight, near the seaside town of Sandown, for much of Sunday.
Two coastguard helicopters were scrambled to the scene and were spotted circling the ship on Sunday afternoon, and an exclusion zone was set up in the area south of Sandown.
Airspace in a three-mile radius around the ship was restricted, with an order going out at 12.30pm reading: “Pilots are forbidden to fly within the designated area without permission of the aeronautical rescue coordination centre.”
Oil tankers are equipped with numerous security features to safeguard against hijacking attempts and protect their cargo, including safe rooms for the crew.