* Officials banned from talking publicly on South China Sea
* Duterte says maritime patrols will continue
* Gag order may show more coherent strategy - expert (Adds foreign ministry comments on diplomatic protest)
By Neil Jerome Morales
MANILA, May 17 (Reuters) - President Rodrigo Duterte said on Tuesday the Philippines would not waver in defence of its interests in the South China Sea, even though he had barred his ministers from talking about the situation there in public.
China's maritime conduct has been a constant problem for Duterte but he has refrained from criticising Beijing and instead praised its leadership, hoping to secure investment.
But after weeks of rebukes of China by his ministers over the presence of hundreds of fishing vessels in the Philippines' Exclusive Economic Zone (EEZ), he told his ministers on Monday they must refrain from discussing the matter.
"If we talk, we talk but just among us," he said in a televised address.
On Tuesday, he said his order should not be construed as weakness and that maritime patrols must continue.
"Our agencies have been directed to do what they must and should to protect and defend our nation's interest," Duterte said in a statement. "We will not waver in our position."
Beijing claims almost the entire South China Sea and has built military installations equipped with missiles on reefs in disputed areas, including within the Philippine EEZ, alongside a constant presence of coastguard and fishing vessels.
Duterte's defence and foreign ministers and his legal adviser have taken strong positions lately on what they have called a "swarming and threatening" presence of Chinese vessels they believes are manned by militias.
China's embassy in Manila has denied the presence of militias. It did not respond to requests for comment on Monday and Tuesday.
The gag order could lessen tensions at the rhetorical level, said Aaron Jed Rabena of the Asia-Pacific Pathways to Progress, a Manila-based think tank.
"It could be that President Duterte has realised that it's high time for his administration to speak with one voice given the mixed signals...which show a government that is incoherent," Rabena said.
The same day Duterte announced the gag order, the foreign ministry filed another diplomatic protest against China over the annual summer fishing ban Beijing imposed in the South China Sea from May 1 to August 16, saying it was "a violation of Philippines' sovereignty and sovereign rights".
"And with the new Chinese coast guard law, it effectively grants Chinese coastguard freedom and authority to use force within what it considers its maritime jurisdiction," Foreign Ministry official Marie Yvette Banzon-Abalos said.
Abalos was referring to a law that China passed in January that allowed its coast guard to fire on foreign vessels.
She said this put at risk the legitimate right of Filipino fishermen to fish in Philippine territory and the exclusive economic zone.
(Reporting by Neil Jerome Morales; Additional reporting by Karen Lema; Editing by Nick Macfie, Martin Petty)
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