Three persons close to gangster Vikas Dubey, who was involved in the ambush of policemen in Kanpur, have been arrested from Haryana's Faridabad in a joint operation by Uttar Pradesh STF and local crime branch team, a senior official said here on Wednesday.

Dubey was in Faridabad and had tried to take a room in a hotel, whose CCTV footage went viral, the official said.

"Three persons close to Vikas Dubey arrested from Faridabad. They were identified as Ankur, Shravan and Kartikey alias Prabhat," a senior official told PTI.

Mmeanwhile, the Uttar Pradesh government has increased the reward for the arrest of Dubey from Rs 2.5 lakh to Rs 5 lakh, officials said on Wednesday.

"Cash reward for the arrest of Vikas Dubey has been increased to Rs 5 lakh. It would be given to those providing information about him," additional chief secretary, Awanish Kumar Awasthi said.

Eight policemen were ambushed in Bikru village in Chaubeypur area of Kanpur when they were going to arrest Dubey and fell to bullets fired from rooftops shortly after midnight on Friday.