At least six policemen in India have died after police from two states fired at each other.
The unusual incident happened along the border between Assam and Mizoram states in north-eastern India.
Officials from both sides, including chief ministers, have accused each other of provoking violence.
The firing incident follows months of simmering tensions over a long-running border dispute between the two states.
Assam shares a 164km border with border with Mizoram, and both states contest its demarcation.
The two sides have often sparred over it, sometimes violently. But this was the first time police in the states had fired at each other in a direct confrontation. The officers killed in the attack were from Assam.
On Monday, Home Minister Amit Shah reportedly spoke to the chief ministers of Assam and Mizoram – Himanta Biswa Sarma and Zoramthanga – and urged them to ensure peace along the disputed border by finding an “amicable solution” to the problem.
After the recent clashes the central government has deployed the CRPF as a “neutral force” at the disputed border.
Tensions also escalated to an unprecedented level in October 2020 when residents of Assam and Mizoram clashed twice in a week. At least eight people were injured as angry residents torched huts and small shops on both sides.
At the heart of the matter was an “eviction drive” carried out by Assam along a contested part of the border – authorities from the state reportedly burned a farmhouse and crops in the area. The Mizoram government responded by deploying troops in areas which Assam claims is part of its territory.
Residents from both states also blocked key highways, bringing all traffic to a halt for almost three weeks until the central government intervened to defuse tensions.