"Russia is extremely concerned by the news that on both sides of the border there is a build-up of troops and military equipment," the foreign ministry said in a statement.

"The tension in this region has reached a dangerous level. There are worrying reports that New Delhi and Islamabad are not ruling out the use of force against each other," it added.

"Russia calls on India and Pakistan to show the maximum restraint and not allow the situation on the border to develop into one of force," it added, saying that negotiations were the only way out of the crisis.

Pakistan on Friday said the military had moved troops from the tribal areas near Afghanistan, where they are fighting Taliban and Al-Qaeda militants, to the eastern border with India as a "minimum security" measure.

Senior Pakistani security and defence officials described the troop movements as "limited" but Indian Prime Minister Manmohan Singh summoned his military chiefs for a strategy session.

India also advised its nationals to avoid travel to Pakistan, saying it was unsafe for them to be in the country.

India and Pakistan have fought three major wars since their 1947 independence from British rule.