LEH, India (Reuters) – Two Indian officials said Chinese troops were laying a network of fibre optic cables at a western Himalayan flashpoint with India, suggesting they were digging in for the long haul despite high-level talks aimed at resolving a standoff there.

Such cables, which would provide forward troops with secure lines of communication to bases in the rear, have recently been spotted to the south of Pangong Tso lake in the Himalayan region of Ladakh, a senior government official said.

Thousands of Indian and Chinese troops backed by tanks and aircraft are locked in an uneasy stalemate along a 70 km-long front to the south of the lake.

The two sides have accused each other of escalating the most serious confrontation on the border between the nuclear-armed neighbours in decades.

A third Indian official said on Monday that there had been no significant withdrawals or reinforcements on either side since the foreign ministers of the two countries met last week.

“It is as tense as earlier,” he said.

A spokesman for China’s foreign ministry cast doubt on the report of the cable network.

“As far as I know, the relevant report is not true,” the spokesman, Wang Wenbin, said when asked on Tuesday.

China and India would remain in communication through diplomatic and military channels, the ministry spokesman, Wang Wenbin, told a news briefing in Beijing.

Chinese defence officials could not immediately be reached for comment.

In June, 20 Indian soldiers were killed in hand-to-hand fighting with Chinese troops in the area. Both sides had agreed to pull back after that clash, but the Indian army has accused Chinese forces of violating that accord

SECURE COMMUNICATIONS

Above Leh, Ladakh’s main city, Indian fighter planes flew throughout the morning on Monday, their engines booming and echoing across the valley surrounded by brown, barren mountains.

“Our biggest worry is that they have laid optical fibre cables for high-speed communications,” the first official said, referring to the lake’s southern bank, where Indian and Chinese troops are only a few hundred metres apart at some points.

“They have been laying optical fibre cables on the southern bank at breakneck speed,” he said.

Indian intelligence agencies noted similar cables to the north of the Pangong Tso lake about a month ago, the second government official said.

The first Indian official said authorities were alerted to the activity when satellite imagery showed unusual lines in the sand of the high-altitude deserts to the south of Pangong Tso.

The lines were judged by Indian experts – and corroborated by foreign intelligence agencies – to be communication cables laid in trenches, he said, including near the Spanggur gap, among hilltops where soldiers fired in the air recently for the first time in decades.

Indian officials say a build-up in border infrastructure on their side is also likely to have played a part in the confrontation.

The Chinese have complained about India building roads and air strips in the area and Beijing says this triggered the tension.

A former Indian military intelligence official, who declined to be identified because of the sensitivity of the matter, said fibre optic cables offered communications security as well as the ability to send data such as pictures and documents.

“If you speak on radio, it can get caught. Communications on optical fibre cables is secure,” he said.

The Indian military still depends on radio communications, the first official said, although he said it was encrypted.