LONDON -- The U.K. military seized control of an oil tanker that dropped anchor in the English Channel after reporting Sunday it had seven stowaways on board who had become violent.

Defence Secretary Ben Wallace and Home Secretary Priti Patel authorized the action in response to a police request, the British Ministry of Defence said. Police investigations will now continue, and initial reports confirmed the tanker's crew was safe and well, the ministry said.

"I commend the hard work of the armed forces and police to protect lives and secure the ship," Wallace said. "In dark skies and worsening weather, we should all be grateful for our brave personnel."

The incident began Sunday morning on the Libyan-registered tanker Nave Andromeda. The coast guard scrambled two helicopters to the scene, and authorities imposed a three-mile exclusion zone around the vessel.

The Nave Andromeda left Lagos, Nigeria, on Oct. 6 and had been expected to dock in Southampton, England, at 10:30 a.m. Sunday, according to ship tracking website MarineTraffic.com. The tanker had been circling an area about five miles southeast of Sandown on the Isle of Wight since about 10 a.m., tracking data showed.

Chris Parry, a retired Royal Navy rear admiral who is now a fellow at the Royal United Services Institute, told The Associated Press he suspects the stowaways grew violent as the tanker neared port, and the crew retreated to a secure area known as "the citadel" to retain control of the vessel.

The captain probably wanted to avoid taking a fully loaded tanker into the heavily populated area near the Portsmouth navy base, where Britain's carriers are based, as long as this incident was going on, Parry said.

"You don't want this ship anywhere near with this sort of thing going on," he said. "And so the captain probably rather wisely and in consultation with his owners, went to anchor off the Isle of Wight."

Bob Seely, who represents the Isle of Wight in Parliament, said the British government was likely to convene a meeting of its emergency committee to discuss the incident. Trouble on the ship is of particular concern because of the tanker's cargo and because the vessel started out from West Africa, he said.

"I suspect, because of the nature of this, it will be treated as marine counter-terrorism," Seely told Sky News. "The number of people in the U.K. who do that are very limited, and the relevant units will be looking at options, no doubt, as to what we could be doing."

Parry said that such stowaway incidents are not infrequent and are likely to increase as migrants look for new ways to enter Britain.

"I think the most important thing to take away from this is that we have a world that's on the move, and the sea is the physical equivalent to the World Wide Web," he said. "And people will find out how to get between countries by sea, by any other route that gets them from one place to another, where they can obviously advance themselves economically, improve their lives and get away from whatever horrors or disadvantages that they were born into."