NEW DELHI (AP) -- The platoon of Chinese soldiers slipped across the boundary into India in the middle of the night, according to Indian officials. They were ferried across the bitterly cold moonscape in Chinese army vehicles, then got out to traverse a dry creek bed with a helicopter hovering overhead for protection.
They finally reached their destination and pitched a tent in the barren Depsang Valley in the Ladakh region, a symbolic claim of sovereignty deep inside Indian-held territory. So stealthy was the operation that India did not discover the incursion until a day later, Indian officials said.
China denies any incursion, but Indian officials say that for two weeks, the soldiers have refused to move back over the so-called Line of Actual Control that divides Indian-ruled territory from Chinese-run land, leaving the government on the verge of a crisis with its powerful northeastern neighbor.
Indian officials fear that if they react with force, the face-off could escalate into a battle with the powerful People's Liberation Army. But doing nothing would leave a Chinese outpost deep in territory India has ruled since independence.
"If they have come 19 kilometers into India, it is not a minor LAC violation. It is a deliberate military operation. And even as India protests, more tents have come up," said Sujit Dutta, a China specialist at the Jamia Milia Islamia university in New Delhi.
"Clearly, the Chinese are testing India to see how far they can go," he said.
That is not China's stated view.
Chinese Foreign Ministry spokeswoman Hua Chunying said Thursday that Chinese troops had been carrying out normal patrols and had not crossed the boundary.
"China is firmly opposed to any acts that involve crossing the Line of Actual Control and sabotaging the status quo," she said at a daily briefing in Beijing as she was repeatedly questioned about the dispute.
Hua said talks to defuse the dispute were ongoing and that it should not affect relations. "As we pointed out many times, the China-India border issue is one which was left over from the past. The two sides reached important consensus that this issue should not affect the overall bilateral relations," Hua said.
Local army commanders from both sides have held three meetings over the crisis, according to Indian officials. India's foreign secretary called in the Chinese ambassador to register a strong protest. Yet the troops did not move, and even pitched a second tent, Indian officials said.
The timing of the crisis, weeks before Chinese Premier Li Keqiang is to visit India, has surprised many here. The Chinese leader's decision to make India his first trip abroad since taking office two months ago had been seen as an important gesture toward strengthening ties between rival powers that have longstanding border disputes but also growing trade relations.
Manoj Joshi, a defense analyst at the New Delhi-based Observer Research Foundation, said the timing of the incursion raises questions about "whether there is infighting within the Chinese leadership, or whether someone is trying to upstage Li."
Indian External Affairs Minister Salman Khurshid said Wednesday that while he had no plans to cancel a trip to Beijing next week to prepare for Li's visit, the government could reconsider in the coming week.
"A week is a long time in politics," he told reporters.
Indian politicians accused the scandal-plagued government of Prime Minister Manmohan Singh of floundering in fear before China.
"China realizes that India has a weak government, and a prime minister who is powerless," said Yashwant Sinha, a former foreign minister from the opposition Bharatiya Janata Party.
He demanded a stronger response. "A bully will back off the moment it realizes that it's dealing with a country which will not submit to its will," Sinha said.
Former Defense Minister Mulayam Singh Yadav called the government "cowardly and incompetent." He warned that China was trying to annex more territory to add to the spoils it took following its victory over India in a brief 1962 border war.
Defense Minister A.K. Antony countered that India is "united in its commitment to take every possible step to safeguard our interests."
Supporters of the right-wing Shiv Sena party burned effigies of Singh, Antony and other top officials Wednesday, demanding India retaliate by barring Chinese imports.
China is India's biggest trading partner, with bilateral trade heavily skewed in China's favor, crossing $75 billion in 2011.
Analysts feel linking a troop withdrawal to continued trade could work.
"The Chinese have to learn that such aggression cannot be delinked from trade," Dutta said.
Though the two countries have held 15 rounds of talks, their border disputes remain unresolved. India says China is occupying 38,000 square kilometers (15,000 square miles) in the Aksai Chin plateau in the western Himalayas, while China claims around 90,000 square kilometers (35,000 square miles) in India's northeastern state of Arunachal Pradesh.
Analysts said they were baffled by Beijing's motives, since its actions could force India to move closer to Beijing's biggest rival, the United States.
"The Chinese for some reason don't seem able to see that," said Joshi.
China's aggressive posture could also force India to accelerate its own military modernization program, analysts said.
The stand-off may eventually be resolved diplomatically, "but what it really shows is the PLA's contempt for our military capability," former Indian navy chief Sushil Kumar wrote in The Indian Express newspaper.
It could also push the government to agree to the army's longstanding demand to create its own strike corps on the border.
"By needling the Indians, they are helping us to accelerate our modernization," Joshi said.
Associated Press researcher Zhao Liang in Beijing contributed to this report.