MUSE, Myanmar (AFP) - Delivering vaccines to Myanmar's junta, but also to rebel groups that are the generals' sworn enemies, China is playing both sides to fight the coronavirus and strengthen its hand in the messy politics of its southern neighbour.
Beijing has already handed over nearly 13 million doses to the generals, who ousted Aung San Suu Kyi in February and plunged Myanmar and its healthcare system into chaos.
The junta has appeared powerless to halt the spread of the virus, spooking authorities on the other side of its porous, 2,000km frontier with China, where officials are waging a "zero case" war on Covid-19.
So Beijing has quietly shipped thousands of vaccines, medical workers, and construction materials for quarantine centres, multiple rebel groups said.
Chinese Red Cross staff "come to help us sometimes... to help us prevent the Covid-19 pandemic," said Colonel Naw Bu, spokesman for the Kachin Independence Army (KIA).
"But they did not come to stay here," added the colonel, whose group - numbering thousands - controls territory in Myanmar's northern jade-rich hills.
"They just came for a while and went back."
The KIA is one of Myanmar's more than 20 ethnic rebel groups - many of whom control swathes of remote border territory - who have fought each other and the military over the drugs trade, natural resources and autonomy.
But they are all vulnerable to Covid-19.
As a third wave ripped through lowland Myanmar in July, the KIA inoculated 10,000 people in their Laiza headquarters with Chinese jabs, Naw Bu said.
Health workers had also crossed over from China to deliver masks and hand sanitiser, he added.
It is a scene familiar along the porous border.
The Shan State Progress Party rebel group has vaccinated 1,000 people in areas under its control with Chinese vaccines, a spokesman said.
It had ordered a total of half a million, he added.
"Good neighbour" China had also promised to supply doses to the Ta'ang National Liberation Army, based in nearby territory, spokesman Brigadier General Tar Phone Kyaw said.
Meanwhile, in the border town of Muse, men work on a new quarantine centre that will house up to 1,000 beds for traders keen to resume business with the country's giant, Covid-wary neighbour.
The workers are Myanmar nationals, but the building materials were all provided by authorities in China's Yunnan province.
The aid is receiving none of the fanfare of Beijing's diplomacy elsewhere in Asia and across Africa.
"China will as always, according to their needs, provide necessary assistance and support to the Myanmar people in their fight against the epidemic," a Chinese foreign affairs spokesman said when asked if Beijing was helping insurgent groups fight Covid-19.
But Enze Han, a University of Hong Kong associate professor in public administration, said it "makes sense" for authorities across the border to help.
"If China wants to protect itself from Covid-19... it needs to create a buffer zone," he said.
And ethnic Chinese groups, using Chinese SIM cards and currency, live along the border in areas "basically grafted onto the lower belly of China", explained David Mathieson, an analyst formerly based in Myanmar.
If major clashes between rebels and the military broke out - as it did in 2017, sending thousands fleeing into China - it would be a "worst-case scenario" for Beijing, he said.
China - the junta's main ally, which has refused to describe its February ouster of the civilian government as a coup - has sent millions of vaccines directly to the military government.
But with widespread distrust keeping many away from healthcare in junta-controlled territory, analysts say Beijing will continue involving itself in areas where the writ of the Myanmar state runs thin.
"The military government definitely doesn't like it," said Hong Kong University's Han. "But they have no option."