The Bihar government has asked Tamil Nadu to probe the killing of five men, including four from Bihar, who were shot dead by police after being branded bank robbers.
The issue was also raised in the state assembly Friday.
"The state government has taken up the issue seriously and asked the Tamil Nadu government to inquire into the killings," Bihar Animal Husbandry Minister Griraj Singh said.
"The Tamil Nadu government should inquire whether they were killed in a police encounter," the minister said.
Police shot dead the five in an alleged Wedneday midnight gun battle in a Chennai residential locality. Human rights activists have questioned the authenticity of the battle.
Police claimed the five people had been staying in a rented apartment, claiming to be students, and they were linked to bank robberies in Chennai since January.