Curfew was clamped in six areas of Allahabad and educational institutions were ordered closed on Saturday after a mob attacked a police station and damaged several vehicles over the alleged desecration of a holy book inside a place of worship.

Ten policemen, including two sub-inspectors, were injured in the "pre-planned" attack on Kareli police station and 14 people were so far arrested on charges of rioting and inciting communal tension, Uttar Pradesh Director-General of Police Vikram Singh said in Allahabad.

He said the trouble erupted late on Friday night in Kareli area where "a holy book was allegedly desecrated inside a place of worship."

Some people lodged a police complaint and went away after an assurance but a few minutes later, a mob collected outside the police station, throwing stones and damaging vehicles there.

Police used batons and fired in the air to disperse the mob and two companies of PAC and one of RAF were deployed after the situation was brought under control.

"All this proves it was a conspiracy" and not a spontaneous outburst, Singh said while Additional DGP Brijlal added a large number of people would not have gathered in such a short span of time had it not been "pre-planned".

He said curfew was imposed in Kareli, Shahganj, Kotwali, Khuldabad, Atarsuiya and parts Dhoomanganj police station areas and educational institutions across the city were ordered closed for the day as a precautionary measure.