Things could get really messy between China and India - especially now bullets have started to fly.

Soldiers of China and India reportedly exchanged gunfire along the contested border in Ladakh on Monday - the first time that guns have been fired since 1975, the BBC reported.

While no one was reported injured by what were believed to be warning shots, the incident might further deepen animosities after the neighbors' soldiers engaged in hand-to-hand combat earlier this year.

China's military said India's soldiers trespassed in a disputed area in the Himalayas and fired "provocative" shots at patrolling troops and China's soldiers had to return fire. But India rejected the accusations and claimed China soldiers fired rifles into the air.

Military activity along the isolated, high-altitude frontier with tight and sometimes impassable tracks snaking through one of the highest mountain ranges in the world is often disorientating. Exact locations are hard to determine.

In a statement China's military said India soldiers took the "dangerous" step of firing warning shots near its border. China asserted India's actions were provocative and "contemptible."

However, India military officials denied the accusations and said it was China's intimidation and violation of the long-held agreement of avoiding the use of weapons.

According to China's Foreign Affairs spokesman Zhao Lijian, the exchange of fire was the first time peace on the border between the two nations was "broken by gunshots," The New York Times said.

An accord signed in 1996 prohibits the use of firearms and explosives on the "Line of Actual Control" - as the disputed region is known. Nevertheless, troops have come to blows before.

Meanwhile, India's military analysts said the current situation was on track for a dangerous deadlock. Neither China nor India wants to start a shooting war. But none of the two has any intention of backing off, either, they said.