Beijingi intensified its warnings to Indian troops to get out of a contested region high in the Himalayas where China, India and Bhutan meet, saying China's "restraint has its limits."
Indian troops entered the area in the Doklam Plateau in June after New Delhi's ally Bhutan complained that a Chinese military construction party was building a road inside Bhutanese territory.
Beijing says Doklam is located in Tibet and that the border dispute between China and Bhutan has nothing to do with India. It has demanded that Indian troops withdraw unilaterally before any talks can be held on the matter.
On Friday, state broadcaster China Central Television carried video that it said showed an army unit in an unidentified part of Tibet carrying out live-fire firing exercises "in the past few days."
A commander sitting in a vehicle shouted "3, 2, 1, fire!" into two telephones and a missile was launched into the sky. Troops were shown loading and firing other artillery.
The report that was also carried in other state media did not mention the dispute with India, and said that the unit has already been training for three months.
It appeared to be an attempt to increase pressure on India, however, along with strongly worded statements this week from China's foreign and defence ministries.
Chinese defence ministry spokesman Ren Guoqiang said that while Chinese armed forces had shown "utmost goodwill" and a "high level of restraint" in the face of the Indian troops, that restraint "has its limits."
"No country should underestimate the Chinese forces' confidence and capability to safeguard peace and their resolve and willpower to defend national sovereignty, security and development interests," Mr Ren said.
China and Bhutan have been holding talks over their border dispute since the 1980s and Bhutan feared the road construction would affect the process of drawing their boundary. India said its troops were attempting to urge the Chinese forces not to change "the status quo" and that any construction would have "serious security implications for India."
In New Delhi on Thursday, external affairs minister Sushma Swaraj told parliament that India was concerned about China's actions on the ground in Doklam affecting the tri-junction boundary point between Bhutan, China and India and the India-China border in the region.
She said India would "keep engaging with China to resolve the dispute."
"War is not a solution to anything," Swaraj said. "Patience, control on comments and diplomacy can resolve problems."
Experts in India say that by building the road, China may be able to gain access to a narrow strip of Indian land known as the Siliguri Corridor or Chicken's Neck. If China was able to block the corridor, it would isolate north-east India from the rest of the country.
On Wednesday, China's Foreign Ministry issued a document setting out what it called "the facts" about Indian troops "trespassing" into Chinese territory, calling on India to immediately and unconditionally withdraw and saying Beijing would work with Bhutan to resolve the boundary issue.
The document says that as of the end of July, more than 40 Indian border troops remained, down from when more than 270 Indian troops with weapons and two bulldozers advanced more than 100 meters into Chinese territory on June 16.
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