China criticised Vietnam on Saturday for its offshore exploration of oil and gas in the contested South China Sea after Hanoi complained that three Chinese patrol boats had challenged a Vietnamese ship, Reuters reported. The Vietnamese ship, the Binh Minh 02, detected the Chinese patrol boats approaching on radar at about 5 a.m. on Thursday (2200 GMT on Wednesday), the official Vietnam News Agency reported. About an hour later, the three Chinese boats intentionally ran through the area where the Vietnamese ship was working, snapping cables the ship was using, then left the scene after about three hours, it said. China's Foreign Ministry implied the fault for the incident lay with Vietnam. "China's stance on the South China Sea is clear and consistent. We oppose oil and gas operations conducted by Vietnam, which have undermined China's interests and jurisdictional rights in the South China Sea and violated the consensus both countries have reached on the issue," ministry spokeswoman Jiang Yu said. "What relevant Chinese departments did was completely normal marine law-enforcement and surveillance activities in China's jurisdictional sea area," she said in a statement posted on the ministry's website (www.mfa.gov.cn). "China has been committed to safeguarding peace and stability in the South China Sea. We are willing to work together with relevant parties to seek a solution to related disputes," Jiang added. Vietnam's Foreign Ministry protested against the incident by passing a diplomatic note to representatives of the Chinese embassy in Hanoi on Thursday. The South China Sea covers an area of more than 648,000 sq miles (1.7 million sq km), containing more than 200 mostly uninhabitable small islands, rocks and reefs. China, Vietnam, the Philippines, Malaysia, Brunei and Taiwan all claim territories in the sea, which covers an important shipping route and is thought to hold untapped oil and gas reserves. The incident this week took place in an area called Block 148 about 120 km (80 miles) off the south-central coast of Vietnam from the beach town of Nha Trang, the Vietnamese news agency said.