Three low intensity blasts were reported from different places on Jangli Maharaj road in Pune on Wednesday.
JM road is a popular hang-out for college students.
The three locations of the blast have been identified. One bomb was placed in a cycle carrier, one in a dustbin and one in Dena bank.
The police is concerned as the blasts seem coordinated.
Television news channel Times Now has reported a fourth blast outside Garware College.
DNA's Saikat Datta, a veteran internal security correspondent reports from Delhi, "Pune has had an unfortunate association with radical elements. The blasts come close after the anniversary of the Mumbai blasts last year. The Indian Mujahideen also recruited many of its cadres from Pune."
Team DNA reports: One person reportedly injured has been rushed to the hospital. Doctors say injuries are minor. The Pune ATS has rushed to the spot. All four blasts reported so far are on Junglee Maharaj Road in the heart of the city. Its a crowded area and is busy on the eve of Rakhsha Bandan.
The four locations so far: Dustbin outside McDonald in Bal Gandharva Chowk, Dustbin opposite McDonald near Dena Bank, and near R Deccan Mall. Two bombs were planted in baskets on bicycles, and the two in dustbins were in plastic bags. Ammonium Nitrate is said to have been used. 9 volt batteries were used to trigger the blast.
NIA teams have left for Pune from Mumbai and Delhi.
Team DNA Pune further reports:
The area has been cordoned off .
Though the news channels are claiming that there have been five blasts, there have been only four so far and the fifth is a suspected bag.
A timer device is suspected to have been used.
Dayanand Bhaurao Patil, a local tailor, spotted a bag lying unattended, and it was while he tried handling it, the bomb went off.
Patil injured both hands has been shifted to Sasoon Hospital in Pune.
His injuries were minor and the doctors declared him out of danger.
Another explosion, around the same time as the one at Bal Gandharva Chowk, took place in a garbage bin outside McDonald, which was crowded as usual, but none were injured.
All the blasts occured within half a km of each other.
The third bomb that went off near Dena Bank, opposite McDonalds, was planted on a red bicycle in a white bag on the front basket.
The fourth blast occurred opposite a KFC in R Deccan Mall. Again, the bomb was placed on a bicycle
The police found the fifth suspect bomb in a carry bag on a bicycle, near McDonalds. The bomb was diffused.
The police has cordoned off the whole of JM Road to check for any more such cycles.
Police deactivate seventh bomb in controlled detonation.
Efforts to diffuse the bomb found at Kalmadi Petrol Pump were underway since 9.30 pm, which then detonated at 9:33 pm.
No injuries were reported.
150 People sitting at the Anna Andolan at Bal Gandharva Chowk did not even notice the blast until the BDDS reached the spot, after which commotion was created.
Bomb Disposal experts say the moist weather reduced the intensity of the blasts and also avoided some blasts.
Picture of the blast tweeted by Rajpal @richirajpal
According to bomb disposal experts the moist weather reduced the intensity and avoided some blasts.
Home Secretary RK Singh says that terror angle cannot be ruled out in Pune explosions as it appears to be planned attack.
Security has been stepped up in Jaipur following the Pune explosions.
The news of the blasts has resulted in major traffic jams in and around JM road.
News channel NDTV tweeted - "Injured person being treated as a suspect..we want to know why he was carrying a packet: Home Secretary RK Singh"
Team DNA Pune reports:
It is interesting to note that all the blasts which rocked the city have been kept on the left hand side of the road while going from Bal Gandharv auditorium towards Deccan Gymkhana. One bomb which was kept on left hand side of the road was found diagonally opposite to Mc Donalds restaurant and was diffused. Out of five blasts four blasts exploded in a matter of 15 minutes between 7.30 and 7.45 pm while the fifth blast took place at around 9 o’clock. The one which was diffused was at around 9.20 to 9.25 pm.
The Southern Command Head Quarters has sent their Bomb Disposal Squad for parallel checking after an appeal from the Civil Administration.
Sole suspect Dayanand Patil who was injured while he was carrying the bomb and was admitted to Sassoon Hospital has been taken into custody, said Home Secretary RK Singh.
14 states have been put on high alert following the blast.