UK police and coastguard staff were dealing on Sunday afternoon with an incident involving stowaways that apparently turned violent on a Navios-owned product tanker off the Isle of Wight in English Channel.

Two coastguard helicopters were scrambled to the scene and were spotted circling the unladen 75,000 dwt Nave Andromeda (built 2011) after it sent out a Mayday and adopted a zigzag course, reports from the scene said.

The BBC reported the crew had retreated to the vessel's secure citadel for their own safety after up to seven Nigerian stowaways turned violent after being discovered.

The defence correspondent of a local newspaper suggested there was evidence military personnel were being mobilised on water and by helicopter, although the Ministry of Defence said it was not involved in the operation.

“We are aware and dealing with an ongoing incident on board a vessel which is situated south of the Isle of Wight," local police said in a statement.

Stowaways

The incident involved a small number of stowaways, Sky News reported.

Police did not immediately confirm the details, while the UK Home Office, which is responsible for border control, did not have any immediate comment, Reuters reported.

An 8 km (5 mile) exclusion zone has been set up south of the Isle of Wight, with the vessel now at anchor, reports said.

Refinitiv vessel tracking data showed the Liberia-flagged tanker had been expected to arrive in Southampton on Sunday morning. The vessel had departed from Lagos, Nigeria, the data also showed.

Spot trading

The LR tanker is owned by Navios Maritime Acquisition Corp, although it was reported sold to clients of AVIC Leasing in early 2019, according to Clarksons data.

The vessel operates in Navig8’s LR8 pool and trades in the spot market, according to the Navig8 website.

Bob Seely, the member of parliament for the Isle of Wight constituency closest to the vessel, told Sky News he expected the incident to be handled by marine counter-terrorism forces, but that it was too early to call it a hijacking, Reuters reported.

Mick Cash, general secretary of the maritime union RMT, reportedly said: “We urge the UK Government to do all it can to prevent any harm coming to crew or anyone else on the Nave Andromeda.

“This is a troubling incident which must not escalate to further jeopardise crew welfare or maritime safety in what is an extremely busy area for merchant shipping.

“We must call on all parties, including the Greek shipowner, to take action to resolve this incident safely and quickly.”

Crisis managers handling the situation have been contacted for comment.