Eight police personnel, including a deputy superintendent of police, were gunned down in a village near the city by the henchmen of a criminal who lost two of them in a firefight later, officials said on Friday.
Seven others, including a civilian, were injured in the attack from a rooftop on a police team after it entered Bikru village past Thursday midnight to arrest Vikas Dubey, a history-sheeter who has faced about 60 criminal cases.
The attackers fled, snatching weapons from the dead and the wounded policemen.
Police then sealed the entire area and began a combing operation, which led to another encounter with Dubey's men in Nivada village. There, police killed Prem Prakash and Atul Dubey, and recovered a snatched pistol.
They were looking for the other members of the gang and the rest of the weapons. The snatched weapons included an AK-47 rifle, an INSAS rifle, a Glock pistol and two .9mm pistols, a police spokesman said.
Inspector General (Special Task Force) Amitabh Yash claimed that the weapon used in the initial attack was a rifle seized from Dubey by the Special Task Force when they arrested him in Lucknow's Krishna Nagar in 2017.
The automatic rifle was released into the custody of someone else by the court. Police said they will investigate further into this.
Hours after the attack, Uttar Pradesh Chief Minister Yogi Adityanath came under flak from the opposition -- including Congress leader Rahul Gandhi -- over the law and order situation in the state.
The failed police raid at Bikru followed the registration of another case against Vikas Dubey, who was accused in 2001 of killing a senior Bharatiya Janata Party leader in 2001.
This time Rahul Tiwari of Jadepur Gharsa had lodged an FIR at Chaubeypur police station against Dubey and four other, accusing them of an attempt to murder.
Uttar Pradesh Director General of Police H C Awasthi said the criminals might have got an inkling of the raid.
Dubey's henchmen put up roadblocks to stop policemen from reaching their hideout. As they got off from their vehicles at one hurdle, a hail of gunfire caught them by surprise.
Policemen fired back but Deputy Superintendent of Police Devendra Mishra, three sub-inspectors and four constables died, officials said.
Additional Director General (Law and Order), Inspector General (Kanpur) and the Senior Superintendent of Police (Kanpur) rushed to the spot after learning about the attack.
A forensic team also arrived there.
Besides Deputy SP Devendra Mishra, who was posted as the circle officer in Bilhaur, others killed in the attack were sub inspectors Mahesh Chandra Yadav, Anup Kumar Singh and Nebu Lal, and constables Jitendra Pal, Sultan Singh, Bablu Kumar and Rahul Kumar.
Two sub inspectors, three constables, a home guard and a civilian were injured, a spokesman said.
Late in the evening, police announced a Rs 50,000 reward for information leading to Dubey's arrest.
Officials said Dubey was an accused in the murder of Santosh Shukla, a minister of state-rank BJP leader, inside a police station in 2001. But he was acquitted.
Chief Minister Yogi Adityanath visited Kanpur to pay tributes to the slain policemen and offer condolences to their families.
He directed the state police chief to take stringent action against the culprits. The Opposition parties too condoled the deaths and targeted Adityanath over crime in the state.
"Another proof of 'goonda raj' in UP. When police are not safe how can the people be?" Congress leader Rahul Gandhi tweeted in Hindi.
Party general secretary Priyanka Gandhi Vadra said criminals have no fear in the state. "From the common man to policemen, no one is safe," she added.
The Samajwadi Party called UP 'Hatya Pradesh' (land of murders), where criminals "patronised by those in power"killed policemen. It said this "connection" must be exposed.
Bahujan Samaj Party supremo Mayawati termed the incident "shameful and unfortunate".