Beijing (CNN) -- China Tuesday blamed its neighbors for escalating tensions in the South China Sea, one day after the Vietnamese navy held a live-fire drill in disputed waters.

"Some countries took unilateral actions to impair China's sovereignty and maritime rights and interests, released groundless and irresponsible remarks with the attempt to expand and complicate the disputes," said Foreign Ministry spokesman Hong Lei at a regular press briefing.

Beijing and Hanoi have exchanged increasingly heated words in recent weeks, accusing each other of territorial intrusions in the South China Sea, which is claimed in whole or in part by China, Vietnam, the Philippines, Malaysia, Brunei and Taiwan.

The vast area of waters, dotted with partially submerged atolls and reefs, contain some of the world's busiest shipping lanes and are thought to hold large deposits of oil and natural gas.

Hanoi authorities have announced a few recent incidents, charging that Chinese ships last week intentionally severed electric cables on Vietnamese survey vessels in Vietnamese waters. Beijing has countered that Vietnamese vessels have been illegally surveying in Chinese waters and harassing Chinese fishing boats.

Computer hackers from both sides have also attacked websites in the other country, posting nationalistic images and messages, according to Chinese media reports.

Although tensions flare up periodically among the various claimants of the disputed waters, the current situation is drawing more international attention amid China's fast-growing political and military power.

The United States officially stays neutral in the disputes, despite some Congressional calls for a more forceful stance to balance China's clout. Secretary of State Hillary Clinton, however, has expressed Washington's willingness to facilitate multilateral talks on the issue.

"The United States has a national interest in freedom of navigation, open access to Asia's maritime commons and respect for international law in the South China Sea," she said last July at a regional security meeting in Hanoi.

Chinese analysts see the United States using the South China Sea issue as a new way to contain China's rise.

"The United States used to have Taiwan as its main bargaining chip in the region," said Zhang Xizhen, a professor of Southeast Asian studies at Peking University. "Now that tensions across the Taiwan Strait have calmed down, they are turning to the South China Sea."

"Although the U.S. claimed neutrality on the issue, if conflicts arise in the area, they may use it as an excuse to intervene," he added.

The Beijing leadership balks at any notion of "internationalizing" the dispute, in sharp contrast to a recent comment by Vietnamese officials welcoming foreign involvement.

"China always maintains that countries directly related to the issue should conduct bilateral negotiations and friendly consultations," Foreign Ministry spokesman Hong said.

"China is trying to safeguard its own legitimate rights and interests, not infringing on other countries' rights," he added. "Justice lies in the heart of the people."