Story highlights China has urged the Philippines to "guarantee the safety" of fishermen accused of poaching

12 Chinese nationals were arrested on April 8 after their ship ran aground on a reef

The coral reef was the same marine park where a U.S. Navy minesweeper ran aground

Tubbahata Reef is a UNESCO World Heritage site with restricted access

China has urged the Philippines to "guarantee the safety and legitimate rights" of fishermen who have been taken into custody for poaching after their vessel ran aground on the protected Tubbataha Reef -- the latest incident in often tense relations among nations in the South China Sea.

Foreign Ministry spokesperson Hong Lei made his comments on Thursday, state-run Xinhua reported , a day after Philippine authorities formally charged 12 fishermen with poaching and attempting to "corrupt public officials," the Tubbataha management office said in a news release.

The 12 Chinese nationals were arrested on April 8 after their ship ran aground on the reef. The fishermen also faced administrative charges for for illegally entering Tubbataha Reefs Natural Park and for damage to the reefs. Crews will be sent to remove fuel from the 500-ton vessel to attempt to float it off the seabed, according to park authorities.

The coral reef was the same that a U.S. Navy minesweeper ran aground and damaged the reef on January 17. Earlier this week, Philippine officials said they would be sending the U.S. government a $1.5 million bill for damage to the reef.

Photos: Photos: End of the USS Guardian Photos: Photos: End of the USS Guardian End of the USS Guardian – The stern of the USS Guardian, the last piece of grounded ship, is removed by a crane vessel on Saturday, March 30. The U.S. Navy minesweeper became trapped on a reef off the western Philippine island of Palawan on January 17. The Navy has pledged to clean up debris and restore the reef as much as possible. Hide Caption 1 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – A crane vessel lifts the bow of the USS Guardian on Tuesday, March 26. Hide Caption 2 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – The crane vessel pulls the bow off the ship on March 26. Hide Caption 3 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – The crane vessel removes a hull section on Wednesday, March 27. The U.S. Navy expects the Guardian to be completely removed from Tubbataha Reef by mid-April, an official says. Hide Caption 4 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – The U.S. Navy and Philippines authorities are working to dismantle the ship. Hide Caption 5 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – Brandon Berry grinds through steel in the engine room in preparation for removing machinery. Hide Caption 6 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – The USS Guardian's funnel section is lifted Tuesday, February 26, as a task force works on removing equipment. Hide Caption 7 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – The USS Guardian rocks in the waves on February 8. Hide Caption 8 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – The Malaysian tug Vos Apollo removes diesel fuel and human wastewater from the USS Guardian on January 28. Hide Caption 9 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – Waves crash against the USS Guardian in January. The minesweeper is estimated to have damaged 4,000 square meters of the Tubbataha Reef, a UNESCO World Heritage site. Hide Caption 10 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – In this undated photo, a U.S. Navy diver moves damage control equipment and other materials to be unloaded from the USS Guardian. Hide Caption 11 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – The Guardian on the Tubbataha Reef on January 19 in a handout photo from the Philippines military. Hide Caption 12 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – Anti-riot police disperse protesters in front of the U.S. Embassy in Manila on Friday, January 25. The Filipinos were demonstrating against the grounded U.S. Navy minesweeper and called for the pullout of American troops stationed in the Philippines. They splattered the police with paint. Hide Caption 13 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – Malaysian tug Vos Apollo, foreground, prepares to help remove fuel from the USS Guardian while a U.S. Navy boat approaches with a salvage team on Thursday, January 24. Hide Caption 14 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – A U.S. Navy salvage assessment team boards the USS Guardian on Wednesday, January 23, in the Sulu Sea. Hide Caption 15 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – A member of the Philippines coast guard approaches the USS Guardian on Tuesday, January 22, in a handout picture from the Philippines coast guard. Hide Caption 16 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – A diver from the Philippines coast guard measures coral damage on the Tubbataha Reef on January 22 in another handout photo. The reef is a Philippines national park and UNESCO World Heritage Site. Hide Caption 17 of 18 Photos: Photos: End of the USS Guardian End of the USS Guardian – Student activists scuffle with police in front of the U.S. Embassy in Manila during a January 19 protest condemning the minesweeper's grounding. Hide Caption 18 of 18

Tubbahata Reef is a UNESCO World Heritage site that is home to about 500 species of fish and 350 species of coral as well as whales, dolphins, sharks, turtles and breeding seabirds.

Elsewhere in the region, an agreement between Japan and Taiwan on fishing rights among disputed islands in the East China Sea has angered Beijing. Lei told reporters Beijing is China is "seriously concerned" about the fishery agreement, Xinhua reported.