Manila - The Philippine government on Monday called for stepped-up security in dangerous waters off Somalia, where 90 Filipino seafarers were being held captive by pirates in separate hijacking incidents.

The call came after pirates seized a freighter, with 23 crew members, including 18 Filipinos.

Presidential deputy spokesman Lorelei Fajardo said the government was exhausting all means to free the 90 Filipinos still in captivity off Somalia.

The Philippine government "has been continuously calling for increased security in these dangerous waters, areas which have been declared risk zones," she said.

"The Philippine government will do all it can to secure the release of our seamen," she added.

In the latest hijacking, pirates seized a Japanese-owned freighter with 23 crew, 18 of whom are Filipinos, on Saturday. The 20,000-ton Chemstar Venus was carrying unidentified chemicals when it was seized.

Foreign Undersecretary Esteban Conejos said the Department of Foreign Affairs was confirming the identities of the 18 Filipinos on the Chemstar Venus.

The new hijacking was reported after pirates freed the M/T Stolt Valor, which was hijacked on September 15, also on Saturday.

Conejos said two Filipino seafarers - engineers Israel Lumpas, 28, and Ernesto Cuartero, 58 - were among the Stolt Valor's crew. He could not confirm if ransom was paid for the release of the ship and its crew. (dpa)