Ruili, Yunnan province, has collected 246,686 samples to test for the novel coronavirus this week, after launching the free program across the city on Tuesday morning, officials said at a news conference on Thursday.

Ruili, which lies on the border with Myanmar, reported two COVID-19 cases among illegal immigrants on Sunday.

"No symptoms of the coronavirus were found in the 95,362 tests of residents that have been completed," said Gong Yunzun, Ruili's Party chief. "All sample collection work will be completed by Saturday."

People who refuse to be tested after that will be compelled to comply and will be placed under 14-day quarantine at designated locations at their own expense, Gong said.

He added that the government should carry out a rapid, high-quality testing campaign and ensure that nobody was missed during the collection work.

The China-Myanmar border in Ruili stretches 170 kilometers, with residents on both sides interacting closely for a long time. That puts great pressure on border control authorities, Gong said.

"In response to the present situation of epidemic prevention and control, we need to strengthen communication and coordination with Myanmar to have effective border management," he said.

"Currently, the overseas pandemic situation is still severe, so we have to face the pressure of keeping the coronavirus out of China — at both land borders and waterways. To avoid any risk of spread across Yunnan, and even the whole country, we have made border management our top priority."

The city is ramping up border controls such as locking down all border villages, prohibiting cross-border movement and heightening precautions against illegal immigration.

On Wednesday, the government released a letter in Chinese, English and Burmese to all foreigners in Ruili, explaining the epidemic prevention and control policies and announcing the creation of a 24-hour foreign language consultation hotline.

"We have received nearly 100 calls from foreigners mainly concerned about the sampling locations and process of the free coronavirus tests, sample registration certificate type, health code registration and test results," said Gong. "All their questions have been answered and resolved."

He added that all the foreigners received warm care from community staff and actively cooperated in the sampling effort.

On Friday, no new confirmed or asymptomatic cases were reported in Ruili.