The U.S. and its allies should put more pressure on Somali pirates on shore, before they reach commercial ships off the Somali coast, a top Navy commander said Wednesday.

Vice Adm. Mark Fox, who is commander of the U.S. Navy's Bahrain-based Central Command fleet, warned that the pirates' growing use of larger, often commandeered ships, is a "game-changer" that allows them to go farther out to sea where Navy ships are not often present.

The pirates' links to al-Shabab insurgents are also a worry, Fox said.

Fox recommended more effort to hit pirate supply lines and track their money. He stopped short of calling for a greater use of military force, but he said the coalition must go after pirates with the same intensity they use when targeting terrorists.

"We have not used the same level of rigor and discipline in terms of following the money on the counter-piracy piece as we have the counterterror," Fox told reporters during a breakfast meeting. "We should be applying the same techniques."

Since last September there has been a significant increase in pirate activity, stretching further out from the Somali coast. According to Fox, the number of hostages taken by pirates has jumped from about 350 to 770 over that time period. He said the pirates are now operating in what he called eight "action groups" in the region, and each includes at least one large mothership and a number of smaller skiffs.

Asked whether he would have the authority to sink such a ship if a US vessel came upon one, Fox said the Navy doesn't have the rules of engagement that would allow a commander to do that.

U.S. officials to date have said they see no evidence of direct ties between Somali-based pirates and al-Shabab terrorists, but Fox laid out the strongest description yet of possible links.

"Al-Shabab is responsible for a lot of training activity and camps and that sort of thing in Somalia," he said. "The pirates use these things. There cannot be a segregation between terrorist activity, in my mind, and counter piracy. We can't be passive and hopeful it doesn't happen."

He said a key effort should be following the money trail, tracking where pirates get their fuel, supplies, ladders and outboard motors. And he said that not all of that activity has to be in Somalia, but could be spilling over into other nearby countries

"I'm not advocating we suddenly just come out with guns blazing and just change everything," said Fox. "But I would advocate that we used the same techniques that have been successful in our counterterror that we have not heretofore used in our counter-piracy."

So far, he said there has not been a broad agreement to commit the counterterrorism resources needed to do that.

Before last fall, the pirates were generally using small boats that were limited in how far they could go or how well they could maneuver in rough seas. But in recent months, they have begun using the larger ships they commandeered to sail more than 1,000 miles out from the coast, where there are fewer Navy ships patrolling the area.

Shifting to a counterterror approach has not been embraced by U.S. and its allies. Often such a move would suggest more lethal strikes, and it could also trigger renewed debate over whether countries or companies should pay the increasingly higher ransoms for the ships and crews.

Treating piracy as a law enforcement matter has reinforced moves to do whatever is necessary to protect the hostages and pay for their release. But under a counterterror strategy, nations insist they do not negotiate with terrorists.

"If we could reroll tape, we would say no ransoms paid," Fox said, "but that cow is out of the barn."

Companies, he said, want to get their crews back. But, he added, "we've got to find a way to break this cycle of increasing success on the pirates' part."