A TV grab of security officials searching debris at the site of the explosion. (AFP)

Bangalore, July 25 (ANI): At least three people were killed and 20 injured in seven serial blasts that hit Bangalore city this afternoon.

The blasts took place between 2.30 p.m. and 4.00 p.m. at the Madivala bus stop, Hossur road, Adugudi, Koramangla, Mysore Road and Nayadahalli.

Bangalore Police commissioner, Shanker Bidri confirmed seven blasts that rocked the Bangalore city and said that the low intensity crude bombs were triggered by a timer.

Bomb disposal squads have reached the blasts sites.

Schools, colleges, cinema halls and commercial complexes have been shut down.

High alert has been sounded to metros and State capitals.

The injured have been admitted to the St Johns Hospital in Bangalore.

State Minister for Home Affairs Shakeel Ahmad said that these blasts are well planned act of terror organised by militant organisation but he refrained from naming any particular terrorist outfit.

Update: Police say that gelatine sticks with the effect of one or two grenades have been used as crude explosives. The timer devices may have been activated by mobile phones. The mobile network was temporarily jammed thereafter.

Indian shares suffered losses to more than 3.5 percent on Friday after reports of blasts had spread.