They said the vessels had bulbous bows and were accompanied by two Chinese coast-guard ships. Together with Chinese fishing vessels, they kept on hampering Vietnamese vessels, occasionally throwing stones and bottles.
China still has a fleet of between 110-115 ships around the rig, including about 40 coast-guard vessels, about 30 cargo ships and tugboats, 35-40 fishing vessels and four military ships.
The Vietnamese surveillance department said Chinese ships continued to operate in groups to prevent Vietnamese law-enforcement ships from approaching the rig.
They blasted sirens, fired water cannons and showed they were ready to ram Vietnamese vessels any time, the department said.
However, Vietnamese law-enforcement ships persistently maintained their positions about 9-11 nautical miles from the rig.
Vietnamese fishermen continued to trawl for fish about 25-20 nautical miles from the rig, the department said.
VN mission replies to China
Earlier on Thursday, the Vietnamese delegation to the United Nations and the World Trade Organisation in Geneva sent a note protesting against China's actions to other WTO and UN countries.
The messages updated developments on China's illegal placement of an oil rig and provocative actions in Viet Nam's exclusive economic zone and continental shelf.
The note demanded China immediately and unconditionally withdraw the rig and compensate for losses caused to the Vietnamese side.
The Vietnamese delegation rejected what it termed "false and fabricated allegations" from China delivered to international organisations and permanent delegations in Geneva on Monday.
The Vietnamese diplomatic note attested Viet Nam's sovereignty over the Hoang Sa (Paracel) archipelago and completely rebuffed China's "illegal and groundless" claims of sovereignty.
It claimed that the installation of the rig and provocative actions by China in Vietnamese waters were serious violations of the sovereign right and jurisdiction of Viet Nam, added that the actions threatened peace, stability and maritime security in the region.
The note highlighted the Viet Nam's goodwill in pursuing peaceful solutions on the basis of international law and the Declaration on the Conduct of Parties in the East Sea (DOC).
It called on countries and international organisations to continue criticising China and support the settlement of disputes in the East Sea by peaceful measures and on the basis of international law, especially the UN Convention on the Law of the Sea 1982 (UNCLOS).
Late last month, Viet Nam's permanent mission to the United Nations asked UN Secretary-General Ban Ki-moon to send a diplomatic note from the Vietnamese Foreign Ministry to the Chinese Foreign Ministry to mark the 68th session of the General Assembly.
The note protested at China's refusal to end violations of Viet Nam's sovereignty over its exclusive economic zone prescribed by the 1982 UNCLOS, to which both Viet Nam and China are members.
Indonesia steps in
In another development, Indonesian Foreign Minister Marty Natalegawa has called on foreign ministers from ASEAN member nations to convene a meeting ahead of the ASEAN Foreign Ministers Meeting (AMM) in August to assess the increasing tensions in the East Sea.
According to a Philippine diplomat, the proposal was made amid China's increasingly aggressive moves to assert its sovereignty in the sea.
He said the August meeting was expected to be a special ministerial-level meeting that would primarily focus on the East Sea issue, adding that ASEAN leaders were being consulted to fix a date and venue for the meeting.
The diplomat said Indonesia backed the proposal, adding that the meeting will send a strong signal that ASEAN was very concerned about China's growing assertiveness.
He said ASEAN nations were seriously concerned about recent tensions between China and Viet Nam in the Hoang Sa (Paracels) archipelago.
Philippine Foreign Secretary Albert del Rosario told press agencies earlier that Indonesia had offered to serve as a mediator in the dispute.
The Vietnamese surveillance department said Chinese ships continued to operate in groups to prevent Vietnamese law-enforcement ships from approaching the rig.
They blasted sirens, fired water cannons and showed they were ready to ram Vietnamese vessels any time, the department said.
However, Vietnamese law-enforcement ships persistently maintained their positions about 9-11 nautical miles from the rig.
Vietnamese fishermen continued to trawl for fish about 25-20 nautical miles from the rig, the department said.
VN mission replies to China
Earlier on Thursday, the Vietnamese delegation to the United Nations and the World Trade Organisation in Geneva sent a note protesting against China's actions to other WTO and UN countries.
The messages updated developments on China's illegal placement of an oil rig and provocative actions in Viet Nam's exclusive economic zone and continental shelf.
The note demanded China immediately and unconditionally withdraw the rig and compensate for losses caused to the Vietnamese side.
The Vietnamese delegation rejected what it termed "false and fabricated allegations" from China delivered to international organisations and permanent delegations in Geneva on Monday.
The Vietnamese diplomatic note attested Viet Nam's sovereignty over the Hoang Sa (Paracel) archipelago and completely rebuffed China's "illegal and groundless" claims of sovereignty.
It claimed that the installation of the rig and provocative actions by China in Vietnamese waters were serious violations of the sovereign right and jurisdiction of Viet Nam, added that the actions threatened peace, stability and maritime security in the region.
The note highlighted the Viet Nam's goodwill in pursuing peaceful solutions on the basis of international law and the Declaration on the Conduct of Parties in the East Sea (DOC).
It called on countries and international organisations to continue criticising China and support the settlement of disputes in the East Sea by peaceful measures and on the basis of international law, especially the UN Convention on the Law of the Sea 1982 (UNCLOS).
Late last month, Viet Nam's permanent mission to the United Nations asked UN Secretary-General Ban Ki-moon to send a diplomatic note from the Vietnamese Foreign Ministry to the Chinese Foreign Ministry to mark the 68th session of the General Assembly.
The note protested at China's refusal to end violations of Viet Nam's sovereignty over its exclusive economic zone prescribed by the 1982 UNCLOS, to which both Viet Nam and China are members.
Indonesia steps in
In another development, Indonesian Foreign Minister Marty Natalegawa has called on foreign ministers from ASEAN member nations to convene a meeting ahead of the ASEAN Foreign Ministers Meeting (AMM) in August to assess the increasing tensions in the East Sea.
According to a Philippine diplomat, the proposal was made amid China's increasingly aggressive moves to assert its sovereignty in the sea.
He said the August meeting was expected to be a special ministerial-level meeting that would primarily focus on the East Sea issue, adding that ASEAN leaders were being consulted to fix a date and venue for the meeting.
The diplomat said Indonesia backed the proposal, adding that the meeting will send a strong signal that ASEAN was very concerned about China's growing assertiveness.
He said ASEAN nations were seriously concerned about recent tensions between China and Viet Nam in the Hoang Sa (Paracels) archipelago.
Philippine Foreign Secretary Albert del Rosario told press agencies earlier that Indonesia had offered to serve as a mediator in the dispute.
