Stowaways on a cargo ship in the Thames Estuary have threatened the crew, who have locked themselves on the bridge of the vessel.
The ship’s operator has said the four stowaways wanted the ship to navigate close to the coast and were armed with iron tubes they had found on board.
Essex Police said they were responding to a “complex incident” on board the vessel off the coast of Essex and Kent.
The force was called around 9:15am today relating to the safety of the crew on board the cargo ship.
The vessel is the Grande Tema, a 71,000-tonne ship that set off from Lagos, Nigeria, on 10 December and is sailing round in circles in the estuary.
Paul Kyprianou, a spokesman for Grimaldi Lines, the operator of the ship, told Sky News: “We found four stowaways on the vessel.
“The vessel was coming from Nigeria and was bound to Tilbury, and those four stowaways were in the cabin and today they managed to escape from the cabin and they started threatening the crew, requesting the master of the vessel navigating very close to the coast.
“That request was probably because they wanted to jump and reach the British coast.
“The crew reacted and they locked themselves in the bridge of the vessel and so they are safe, we haven’t had any injuries.”
He added: “The master is in continuous contact with the UK authorities, particularly with the Essex police and the coastguard. We are waiting to see what is going to happen. We expect authorities to intervene.”
Mr Kyprianou continued: “They managed to get some, whatever they could find on the vessel, pieces of iron tubes and things like that that they were using in order to threaten.
“It’s a small group, but obviously you can understand it would be scary.
“The problem is the four people free on the deck threatening members and requesting them to get closer. No injuries so far, but obviously it’s a tense atmosphere.”
Essex Police said: “We have received no reports that anyone has been harmed and don’t believe they are at risk.
“We are not currently treating this as either a hostage, piracy or terror-related incident.
“We are working closely with our partners to resolve this incident as quick as possible.”