HANOI, Vietnam -- Three Vietnamese sailors who were held hostage by Somali pirates for more than four years returned home Tuesday, with one father expressing happiness at seeing a son he hadn't heard from in three years.

They were among 26 Asian sailors who were released Saturday after being held since their fishing vessel was seized in March 2012.

The sailors appeared in good health when they emerged from a flight from Nairobi, Kenya, to Noi Bai Airport in Hanoi on Tuesday and were greeted by relatives before having their health checked at a hospital.

Phan Xuan Linh, father of sailor Phan Xuan Phuong, said his son only called the family three times in the first year asking for help and then did not have any contact with him.

"(We were) worried, but did not know what to do," Linh told the Associated Press while waiting for his son's return. "They were pirates, they were lawless and we just prayed for him and did not know who to call for help, because the pirates are similar to terrorists. We had faint hope that my son would return home. Today we are very happy."

The sailors did not speak to journalists upon their arrival at the airport.

The crew from Vietnam, Taiwan, Cambodia, Indonesia, China and the Philippines had been among the few hostages still in the hands of Somali pirates.

The sailors were the crew of the FV Naham 3, a Taiwan-owned fishing vessel seized in March 2012, pirate representative Bile Hussein said Monday. The ship later sank.

Hussein said $1.5 million in ransom was paid for the sailors' release. That claim could not be independently verified.

One member of the crew died in the hijacking and two died of illnesses in captivity.

Piracy off Somalia's coast was once a serious threat to the global shipping industry. Attacks dropped off dramatically after NATO counties, China and India, sent their navies to patrol the waters.

Most hostages held by Somali pirates have been sailors on merchant ships, although European families also have been kidnapped from their yachts while traveling in the dangerous waters.