MANILA (REUTERS) - Filipino protesters plan a second trip to disputed islands in the South China Sea, this time staying a month, a spokeswoman said on Thursday (Jan 21), after China flew a planeload of tourists to an artificial island it has built in the area.

China claims almost the entire energy-rich South China Sea, where about US$5 trillion (S$7.2 trillion) worth of ship-borne trade passes each year. Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.

Last week, Beijing allowed in its first group of tourists, most of them family of soldiers stationed on man-made Fiery Cross in the Spratly Islands, as it began test flights on the 3,000m runway.

"China is now doing what we actually did last month when we landed on Pagasa (Thitu) island," said Ms Vera Joy Baneg, spokesman for the Kalayaan Atin Ito (Freedom This is Ours) group.

Last December, about 50 Filipino protesters, mostly students, made a three-day boat trip to Thitu, one of nine outcrops or islands occupied by the Philippines.

"In April, we will make another voyage to our islands. This time, we will spend a month to visit all the islands we occupy in the Spratleys. We are encouraging all patriotic Filipinos to join us and fight for our territory."

The protesters said Filipino fishermen could no longer use their traditional fishing grounds because large Chinese coast guard ships were driving them away.

They criticise the Philippine government for not doing anything to stop Chinese fishermen from harvesting giant clams and collecting fish with dynamite and cyanide fishing.

"China has established firm and effective control of the South China Sea," Ms Baneg said.