BEIJING (Reuters) - Philippines fishermen threw fire bombs at Chinese law enforcement vessels in the South China Sea, China’s Foreign Ministry said on Tuesday, after Philippines media reported that fishermen had been struck by bottles hurled from China’s coast guard ships.

A Philippine flag flutters from BRP Sierra Madre, a dilapidated Philippine Navy ship that has been aground since 1999 and became a Philippine military detachment on the disputed Second Thomas Shoal, part of the Spratly Islands, in the South China Sea March 29, 2014. REUTERS/Erik De Castro

The reports said that a clash occurred at Scarborough Shoal, an area China seized control of after a three-month stand-off with the Philippine coast guard in 2012. The reports said Chinese coast guardsmen hurled bottles at the Philippines fishermen, who responded with rocks.

China’s Foreign Ministry spokeswoman Hua Chunying said Scarborough Shoal - known by Beijing as Huangyan Island - was Chinese territory which Philippine fishermen had been fishing around illegally.

“Chinese official ships advised the illegally stationed Philippine trawlers to leave, in accordance with the law, but they refused to obey,” she told a daily news briefing.

“Certain people on the ships even waved around machetes and flung fire bombs, carrying out deliberate provocation, attacking the Chinese law enforcers and official boat, confronting China’s law enforcement and seriously threatening the safety and order of the waters around Huangyan Island,” Hua said.

China had strengthened its “management” around the shoal, she added, without elaborating.

A spokesman for the Philippines Foreign Ministry declined to comment, pending an official report “from our concerned agencies”.

China and the Philippines have long exchanged accusations about each other’s behavior in the disputed South China Sea.

China claims most of the energy-rich waters through which about $5 trillion in ship-borne trade passes every year. Neighbors Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.

A spokesman for the U.S. Defense Department, Commander Bill Urban, said Chinese Coastguard vessels had sought since 2012 to block fishing access to the area, “restricting the long-standing commercial practices of others”.

“We are concerned that such actions exacerbate tensions in the region and are counterproductive,” Urban said. He said that the United States, which is a treaty ally of the Philippines, wanted to see claims resolved peacefully in accordance with international law or arbitration.

Last week, the U.S. Navy said it had seen activity around Scarborough Shoal that could be a precursor to more Chinese land reclamation, which China has conducted on a large scale elsewhere in the South China Sea to back its territorial claims.

Navy chief Admiral John Richardson also told Reuters that a ruling expected in late May or early June in a case the Philippines has brought against China over its claims in the International Court of Arbitration in the Hague, could prompt Beijing to declare a South China Sea exclusion zone.