The wife of one of the freed sailors said she was "super happy"
Somali pirates have freed a Japanese tanker and its crew of 23 Filipinos after holding them for five months.
The owner of the ship said securing the release was "difficult and protracted". It is not known if a ransom was paid.
The Philippines is the world's largest supplier of maritime labour, and about 100 of the 300 sailors currently held hostage by Somali pirates are Filipino.
The Manila government has now decided to ban its sailors working on ships travelling through the Gulf of Aden.
Somalia has had no stable government since 1991, fuelling the lawlessness that has allowed piracy to thrive.
Nato warships are patrolling the seas in the area, and over the past weeks have stepped up their action against the pirates, freeing a number of ships.
One of the suspected pirates is due to face trial in New York shortly - the first person to face piracy charges in the US for more than a century.
The Stolt Strength was seized in November 2008 while it was carrying a cargo of phosphoric acid from Senegal to India.
The owner of the vessel, Sagana Shipping Inc, declined to say whether any ransom was paid for Tuesday morning's release.
Doris Deseo, wife of Carlo Deseo, the ship's 31-year-old third mate, told AP news agency: "They have been released, thank God! I am super happy."
Andrew Mwangura, of the East African Seafarers Assistance Programme, told AFP news agency: "We think that something was paid but we don't know what."
Relatives of the crew have said the pirates' ransom demand was haggled down to just over $2m (£1.4m) by last week.
Just before receiving news of the hostages' release, the Philippine government decided to stop its sailors working on vessels that might pass through the Gulf of Aden.
Several government departments are working on the precise wording of the measure, and its scope and efficacy remain unclear.
But Arthur Bowring, managing director of the Hong Kong Ship-Owners' Association, told the BBC: "We do have concerns about how such a measure would work in practice."
Philippine sailors are part of the country's huge remittance economy, in which billions of dollars are earned by the country's citizens working abroad as maids, sailors or construction workers.
Families back in the Philippines depend on the money they send back.
Philippine seamen's groups have attacked the idea of a ban as ridiculous, saying it is empty rhetoric from a government unable to provide livelihoods at home.