MANILA, Philippines >> The Philippines has accused China of aggressively violating an agreement aimed at preventing clashes in the disputed Spratly Islands, the latest in a series of complaints about Chinese incursion in the area claimed by six countries.

Foreign Secretary Albert del Rosario said Tuesday that the latest confrontation in South China Sea islands close to Philippine shore is the most serious challenge to efforts to resolve the dispute peacefully since 1995, when China forcibly took over Manila-claimed Mischief Reef.

The government says it has evidence that show at least six Chinese intrusions in Manila-claimed areas in and near the Spratlys since February. Among the most serious was the reported firing Feb. 25 by a Chinese navy vessel to scare away Filipino fishermen from the Jackson Atoll, a Spratlys area claimed by Manila.

The Philippines, whose poorly equipped forces are no match for China’s powerful military, has resorted to diplomatic protests. President Benigno Aquino III has said his government was preparing to bring its protests before the United Nations.

Del Rosario, in a statement published Tuesday in the Philippine Star newspaper, urged the nations locked in the dispute over the potentially oil-rich region to adhere to international laws to prevent armed confrontations and foster conflict-resolution.

“International law has given equal voice to nations regardless of political, economic or military stature, banishing the unlawful use of sheer force,” he said.

China and the 10-member Association of Southeast Asian Nations, which includes the Philippines, signed a nonbinding accord in 2002 that called on claimants to exercise restraint and stop occupying new areas.

“This very provision is being aggressively violated,” del Rosario said.

The Spratlys, which are believed to be atop vast oil and gas reserves, have long been feared as a potential flash point of armed conflicts in Asia. The chain of barren, largely uninhabited islands, reefs and banks, are claimed wholly by China, Taiwan and Vietnam and partly by the Philippines, Malaysia and Brunei.

They teem with rich fishing grounds and straddle some of the world’s busiest sea lanes.

China has denied its ships intruded into Philippine areas. Defense Minister Gen. Liang Guanglie told an Asian security conference in Singapore last week that China’s military will not be used aggressively against its neighbors.

Philippine Defense Secretary Voltaire Gazmin said that the international community will hold China to its promise. If it reneges, China “will lose face,” Gazmin told a news conference Tuesday.

Chinese media have reported that Beijing plans to install an advanced oil rig in the South China Sea in July. The Philippines has expressed concern and asked China’s embassy last week about the exact location of the planned oil rig and said that it should not be placed in Philippine waters.

In April, China countered a previous Philippine diplomatic protest at the U.N. by saying it has indisputable sovereignty over the Spratly islands that Manila “started to invade” in the 1970s.

Vietnam and Malaysia have also filed protests to the United Nations against China’s claims. The protests are registered with the U.N. Commission on the Limits of the Continental Shelf, which will not rule on a claim if it involves disputed territory unless there is prior consent given by all states involved in the dispute.