Hanoi, Jan 5 (DPA) Vietnam protested a Chinese proposal to begin tourist visits to the disputed Spratly and Paracel Islands in the South China Sea, local media reported Tuesday.

The Chinese State Council announced the proposal Thursday as part of a plan for development of the tourism industry in the Chinese island province of Hainan.

Vietnamese government spokeswoman Nguyen Phuong Nga denounced the Chinese proposal for the islands, which both countries claim, the official Vietnam News reported.

“China’s act seriously violated Vietnam’s sovereignty, running counter to the common understanding reached between senior leaders in both countries,” Nga said.

Last week, Vietnam protested the adoption of an environmental protection law for sea islands by China’s legislature. The law bans construction, the felling of trees, tourism on uninhabited islands and activities that could damage coral reefs.

The new law puts China’s State Oceanic Administration in charge of monitoring compliance. Vietnam objected because the disputed islands were included under the law.

China has occupied the Paracel Islands since 1974 when its troops overwhelmed a South Vietnamese garrison occupying the islands.

Both Vietnam and China are signatories to the 2002 Declaration on the Conduct of Parties in the South China Sea. It commits the parties to resolving the islands’ status through negotiations and provides for freedom of navigation.

Vietnam and China generally enjoy close relations, but the conflict over maritime resources is a persistent source of tension.

Each country submitted maritime territorial claims to the UN Convention on the Law of the Sea in early May and rejected the other’s claims shortly afterward.

The South China Sea is believed to contain substantial undersea oil reserves.

Vietnam, Taiwan, China, the Philippines, Malaysia and Brunei each claim all or part of the Spratlys and the nearby Paracels, and all but Brunei have a military presence on one or more of the atolls.