The main aide of notorious gangster Vikas Dubey involved in the attack in which eight police personnel were killed was arrested in a pre-dawn encounter in Kanpur, a senior police official said on Sunday.
The aide, Dayashankar Agnihotri, was injured in his leg in retaliatory firing by police after he tried to attack them and flee, the official said, adding that no police personnel was hurt.
Police have also taken into custody the sub-divisional officer (SDO) and another employee of the power sub-station from where electricity supply was interrupted on the intervening night of Thursday-Friday at the time of the police raid at Dubey's house in Bikru village.
Police also questioned the man responsible for disconnecting the power supply, a senior police official said, adding that the man confessed to having snapped the power lines on instructions of a caller who claimed that he was calling from the nearby Chaubeypur police station in Kanpur district.
According to sources, the phone number from which the line worker was contacted belongs to the Chaubeypur police station.
However, police have not given any information on who ordered the power supply interruption during the raid.
After being taken into custody, Agnihotri told reporters that Dubey had got a call from someone in the police department informing him about his imminent arrest, and after that he called his men for a face-to-face confrontation with the police.
Allegations had earlier surfaced against Vinay Tiwari, Station Officer of Chaubeypur police station in whose jurisdiction the incident took place, following which he was suspended on Saturday.
It was alleged that Tiwari had alerted Dubey that a police team was on the way to his house to arrest him, following which the gangster and his men attacked the police personnel resulting in the slaying of eight of them.
Dubey is absconding over two days after the incident.
Police sources said Dubey had disabled all the cameras before fleeing the crime scene and took the Digital Video Recorder (DVR) with him.
More than 25 police teams mostly headed by senior officials have carried out raids at hundreds of locations in various districts, police said, adding that they also carried out searches near the border with Nepal and in other states.
Dubey's last location was traced to Auraiya in UP and police have suspected that he has fled either to Nepal or Madhya Pradesh, a police official said.
Police also said that on Saturday, it lodged an FIR against 21 people whose identities have been established and they are mostly residents of Bikru village, and 50-60 other unidentified people in connection with the killing of the eight personnel.
"Dayashankar Agnihotri alias Kallu, the main aide of Dubey, has been arrested during an encounter. Agnihotri always used to accompany Dubey and was staying at Dubey's house," Inspector General, Kanpur Range, Mohit Agarwal told PTI.
"Agnihotri was carrying a cash reward of Rs 25,000. He was named accused in the firing incident on the policemen. In the encounter, he got bullet injuries on his leg," Agarwal said.
Additional Director General of Police, Kanpur, J N Singh told PTI that the encounter took place at around 4.30 am in Kalyanpur area of Kanpur.
Agnihotri was admitted to the Lala Lajpat Rai hospital and police recovered a country-made pistol and two cartridges from his possession, said Superintendent of Police (west) Anil Kumar.
In the early hours of Sunday, police got a tip-off and tried to stop Agnihotri on the Kalyanpur-Shivli road when he opened fire at them. While no police personnel was hurt, Agnihotri got bullet injuries on his leg in retaliatory firing.
IG Agarwal said the cash reward on Dubey's arrest has been increased to Rs 1 lakh from Rs 50,000.
Agarwal said SO Tiwari has been sent to Police Lines.
"He has not been detained. Investigations are going on. If any evidence is found which suggests that Tiwari was part of the conspiracy, then he will be detained," he said.
On the demolition by police of Dubey's house on Saturday, the IG said police had information that Dubey had hidden a lot of arms and ammunition in a bunker and in the walls of the house.
"The walls were broken in order to search for the weapons, and the roof collapsed. Large amount of ammunition was recovered in the digging," the IG said.
Shortly after midnight on Friday, eight policemen had walked into a trap set by Dubey and fell to a hail of bullets fired from rooftops.
They were given a tearful farewell on Saturday as police began demolishing the criminal's lavish hideout in Bikru village, the scene of the bloody crime.
Seven others, including a civilian, were injured in the attack that took place in the early hours of Friday. Later, police sealed the entire area and began a combing operation, which led to another encounter with Dubey's men in Nivada village in which two of them were killed.
The eight men killed in the line of duty, mostly in their 20s and 30s, included Deputy Superintendent of Police Devendra Mishra, 54.
The others are Mahesh Kumar Yadav, 42, Sub-Inspector Anoop Kumar Singh, 32, Sub-Inspector Nebu Lal, 48, and Constables Jitendra Pal, 26, Sultan Singh, 34, Bablu Kumar, 23, and Rahul Kumar, 24.
Their bodies were taken back to their homes where senior police officers attended their last rites.