05:55 GMT, April 16, 2009 Somali pirates captured four more ships and took more than 60 crew members hostage in a brazen hijacking spree, while the American captain who escaped their grip planned to reunite with his crew and fly home to the United States on Thursday.

Capt. Richard Phillips of the Maersk Alabama has been hailed as a hero for offering himself up as a hostage to save his crew. In a dramatic rescue, US Navy SEALs shot three pirates dead Sunday night to free Phillips after a five-day standoff.

Phillips and his 19-man crew will reunite in the Kenyan port of Mombasa tomorrow and fly from there to Andrews Air Force Base in Maryland on a chartered flight, according to the shipping company Maersk. They will be reunited with loved ones at Andrews in a private reception area.

Pirates have vowed to retaliate for five colleagues slain by US and French forces in hostage rescues in the last week, and the top US military officer today said he takes those comments seriously.

But Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, told ABC's "Good Morning America" that "we're very well prepared to deal with anything like that."

Despite Mullen's confident statement and President Barack Obama's warning of further US action, Somali pirates captured two more nautical trophies today to match the two ships they seized a day or two earlier.

The latest seizures were the Lebanese-owned cargo ship MV Sea Horse, the Greek-managed bulk carrier MV Irene E.M. and two Egyptian fishing boats. Maritime officials said the Irene carried 21 to 23 Filipino crew and the International Maritime Bureau reported 36 fishermen, all believed to be Egyptian, on the two boats.

It was not known exactly how many crew the Sea Horse had, but a ship that size would need at least a dozen sailors. NATO spokeswoman Shona Lowe said pirates in three or four speedboats captured the Sea Horse off Somalia's eastern coast on Wednesday - an attack that came hours after the Irene was seized in a rare overnight raid in the Gulf of Aden.

The two Egyptian fishing boats were hijacked in the gulf off Somalia's northern coast but it was not clear if those attacks came Monday or Sunday.

The Gulf of Aden, which links the Suez Canal and Red Sea to Indian Ocean, is one of the world's busiest and most vital shipping lanes, crossed by over 20,000 ships each year.

A flotilla of warships from nearly a dozen countries has patrolled the Gulf of Aden and nearby Indian Ocean waters for months. They have halted many attacks on ships this year, but say the area is so vast they can't stop all hijackings.

Pirates have attacked 78 ships this year, hijacking 19 of them, and 17 ships with over 300 crew still remain in pirates' hands, according to Noel Choong, who heads the International Maritime Bureau's piracy reporting center in Kuala Lumpur.