Somali pirates, apparently undeterred by U.S. and French hostage rescues that killed seven bandits in the past week, hijacked a freighter overnight in the Gulf of Aden, maritime security contractors said Tuesday.

It was not immediately clear who owned the hijacked ship, M.V. Irene E.M., or where it is based. The Irene is at least the third vessel hijacked in a week. The nighttime attack indicates increased technology acquired by pirates who win multimillion-dollar ransoms.

The contractors spoke on condition of anonymity because the hijacking is a sensitive security issue.

The new hijacking comes soon after Navy SEAL snipers rescued Richard Phillips, an American cargo ship captain, on Sunday by killing three young pirates who held him captive in a powerless lifeboat for five days. A fourth pirate surrendered after seeking medical attention for a wound he received in trying to take over Phillips' vessel, the Maersk Alabama.

The 19 crew members of the Alabama celebrated their skipper's freedom with beer and an evening barbecue Monday in an area cordoned off from journalists, said crewman Ken Quinn, who ventured out holding a Tusker beer — a popular brew in Kenya, where the ship was docked.

The next morning, the crew left the cargo ship in the Kenyan resort city of Mombasa and checked into a hotel there. It was not immediately clear how long the crew was planning to stay. Some crew have said they would return home soon, probably by air.

Earlier, the vessel's chief mate was among those urging strong U.S. action against piracy.

"It's time for us to step in and put an end to this crisis," Shane Murphy said. "It's a crisis. Wake up."

President Barack Obama appeared to move up the piracy issue on his agenda, vowing "to halt the rise of piracy" and saying the United States would work with nations elsewhere in the world.

"I want to be very clear that we are resolved to halt the rise of piracy in that region and to achieve that goal, we're going to have to continue to work with our partners to prevent future attacks," Obama said at a Washington news conference Monday.

The U.S. was considering options including adding Navy gunships along the Somali coastline and launching a campaign to disable pirate "mother ships," according to military officials who spoke on condition of anonymity because no decisions have been made.

In Burlington, Vt., Phillips' wife, Andrea Phillips thanked Obama, who approved the dramatic sniper operation that killed the pirates holding him.

"You have no idea, but with Richard saved, you all just gave me the best Easter ever," she said in a statement read by the family's spokeswoman.

The four pirates that attacked the Alabama were between 17 and 19 years old, Defense Secretary Robert Gates said.

"Untrained teenagers with heavy weapons," Gates told a group of students and faculty at the Marine Corps War College. "Everybody in the room knows the consequences of that."

U.S. officials were now considering whether to bring the fourth pirate, who surrendered shortly before the sniper shootings, to the United States or possibly turn him over to Kenya. If he is brought to the U.S., he'd most likely be put on trial in New York or Washington.

Both piracy and hostage-taking carry life prison sentences under U.S. law.

The American ship had been carrying food aid bound for Rwanda, Somalia and Uganda when the ordeal began Wednesday hundreds of miles off Somalia's eastern coast. As the pirates clambered aboard and shot in the air, Phillips told his crew to lock themselves in a cabin and surrendered himself to safeguard his men.

Phillips was then taken hostage in an enclosed lifeboat that was soon shadowed by three U.S. warships and a helicopter. Navy SEAL snipers parachuted from their aircraft into the sea, and were picked up by the USS Bainbridge, a senior U.S. official said.

U.S. Defense officials said snipers got the go-ahead to fire after one pirate held an AK-47 close to Phillips' back. The military officials asked not to be named because they were not authorized to publicly discuss the case.

Snipers killed three pirates with single shots shortly after sailors on the Bainbridge saw the hostage-takers "with their heads and shoulders exposed," Gortney said.

On Friday, the French navy freed a sailboat seized off Somalia last week by other pirates, but one of the hostages was killed. The pirates had seized the sailboat carrying Florent Lemacon, his wife, 3-year-old son and two friends off the Somali coast a week ago.

Two pirates were killed, and Lemacon died in an exchange of fire as he tried to duck down the hatch. Three pirates were taken prisoner in the operation, and are to be brought to France for criminal proceedings

It was not immediately known when or how Phillips would return home.

Before the latest hijacking, pirates were holding some 230 foreign sailors still held hostage in more than a dozen ships anchored off lawless Somalia.