China-India Border Tensions Rise.

Tensions are mounting between India and China over their disputed Himalayan border and shared water resources ahead of a visit to New Delhi next month by Chinese Premier Li Keqiang .

As China's ties with its East Asian neighbors, especially Japan, have become fraught over territorial disputes in the East and South China seas, Beijing and New Delhi have been attempting to dial down historical tensions as bilateral trade flourishes.

But a series of alleged cross-border incidents since mid-April have once again raised the temperature between India and China, who fought a 1962 border war that Beijing won and regard themselves as regional powers.

Indian authorities alleged this week that on April 15 they noticed that Chinese troops set up a post 6 miles inside their territory in the remote Himalayan area of Ladakh and remain there. The de facto border in the area, known as the Line of Actual Control, is disputed.

A week later, Indian media reported that Chinese helicopters flew over an Indian military base in the same area. Indian officials declined to comment on this allegation.

China's military and Foreign Ministry deny the allegations and have attempted to play down New Delhi's allegations that China has grown more assertive in recent months over its territorial claims against India.

A spokesman for China's Defense Ministry, Yang Yujun, said at a news briefing this week that reports of a Chinese incursion were "not true," and that Chinese and Indian border troops remained in communication, according to China state-run news agency Xinhua.

Scholars said the latest friction could be related to a recent Indian program to accelerate road building near the Line of Actual Control to help transport Indian troops.

China may be attempting to attain a "negotiating point to force India to stall its actions close to the border," said Srikanth Kondapalli, a professor in Chinese studies at Jawaharlal Nehru University in New Delhi.

On Friday, India's Defense Ministry and army officials briefed national lawmakers on the alleged incursion. The officials said New Delhi deployed troops in the area and is keeping a close watch on the Chinese positions, said a lawmaker who was present.

A spokeswoman for the Chinese Foreign Ministry said during a news briefing Thursday the allegations wouldn't affect wider border stability or the development of ties between Asian neighbors.

India, too, is playing down the alleged incidents at a time when both nations are forging closer trade ties. Bilateral trade rose by about a third to nearly $76 billion in the year ended March 31, 2012, from a year earlier, and the countries hope to boost this trade to $100 billion by 2015.

"One little spot is acne, which cannot force you to say that this is not a beautiful face," Salman Khurshid, India's foreign minister, told reporters on Thursday. "That acne can be addressed by simply applying an ointment."

Mr. Khurshid will visit China in the second week of May ahead of Premier Li's trip to India, a precise date for which hasn't been released.

Nonetheless, the two sides appear little closer to drawing down the dispute, which has left Chinese and Indian commentators pointing fingers on who should bear the blame for the recent uptick in tensions. Indian officials say two meetings of Chinese and Indian military commanders on the de facto border haven't resolved the dispute.

"This is the most serious incursion by the Chinese in over a quarter of a century," said Brahma Chellaney, professor of strategic studies at the New Delhi-based Center for Policy Research, a think tank. India may be forced to mobilize troops in the area to force China to stand down, he added.

Some Chinese academics, meanwhile, said visible tensions between the countries served neither side's interests.

Shen Dingli, an international-relations scholar at Shanghai's Fudan University, said New Delhi's decision to publicly protest the alleged troop incursion was a sign of weakness by the Indian government.

He said Chinese troop movements, if confirmed, were likely in response to what he described as frequent activity by the Indian military units in the area. "The more you send your troops, the more we need to defend," Mr. Shen said.

Other areas of potential dispute are widening as well. India wants China to allow it to monitor three new dams that Beijing plans to build on the Brahmaputra River, which rises in Tibet before flowing into Indian territory.

Indian Prime Minister Manmohan Singh said he asked Chinese Premier Xi Jinping on the sidelines of a summit last month in South Africa for access to the dams to ensure they don't reduce water flow to India.

India also is concerned about China's growing military might. Beijing is spending heavily on its military, with a focus on its navy, which New Delhi worries could challenge its supremacy in the Indian Ocean region. China military spending is set to rise 11% in 2013 to 720.2 billion yuan ($114.3 billion), a significant portion of which will contribute to Chinese naval capabilities as it takes on missions further from its shores.

The Hindustan Times, an Indian newspaper, this month cited a document prepared by a military advisory body as saying that an increasing number of Chinese submarines ventured last year into the Indian Ocean region. An Indian Defense Ministry spokesman declined to comment on the report.

China has complained about Indian involvement in joint-venture energy projects with Southeast Asian countries in areas of the South China Sea that Beijing claims as its territory.

While India and China have failed to settle its border disputes since the 1962 war, both sides have refrained from aggressive rhetoric on the issue since 2009.

China says the eastern Indian state of Arunachal Pradesh is historically part of southern Tibet. India wants China to hand back territory it calls Aksai Chin, desolate high-altitude salt flats that residents of Ladakh claim as part of its ancient Buddhist kingdom. India's discovery of a Chinese-built road in the region helped spark the 1962 war.

In late 2009, China objected to a visit by Mr. Singh to Arunachal Pradesh to campaign for local elections, saying it was disputed territory. India responded Arunachal was its territory.

At the time, India objected to Chinese investment in infrastructure projects in Pakistan-held Kashmir, another area of the Himalayas that India also claims.

Frontier Friction

The Himalayan 'Line of Actual Control' is a source of dispute:

• 1962 India and China fight one-month border war that Beijing wins.
• 1987 Both sides build up troops on disputed border by the northeastern Indian state of Arunachal Pradesh. War is averted.
• 2009 China complains about Indian Prime Minister Manmohan's Singh's visit to Arunachal Pradesh, territory China claims.
• 2010 Chinese Premier Wen Jiabao visits India with a large trade delegation, promising warmer relations.
• April India alleges China troops cross de facto border in Ladakh, in the northwestern Himalayas.