Preliminary investigation into the twin blasts in Hyderabad has suggested that Improvised Explosive Device (IED) were used to carry out the explosions and the modus operandi was similar to blasts triggered by the banned militant outfit Indian Mujahideen.

"The blasts triggered by IED tied to two bicycles at two sites 100 metres apart and some traces of Ammonium Nitrate were also found from the two spots," police said.

The toll in last evening's powerful explosions has climbed to 16. Five of the 119 injured are stated to be in a critical condition.

Forensic experts of NSG and NIA and state police were examining all materials found from the blast sites and a final report was awaited.

Delhi Police, along with Hyderabad Police, is expected to interrogate an alleged Indian Mujahideen terrorist, arrested by the Special Cell of the Delhi Police from a place in Hyderabad last October.

Maqbool, who is currently in Tihar jail, had said the outfit was planning terror strikes in some places in Hyderabad for which recce had been carried out.

Union Home Secretary R K Singh had said last night that the explosions were "very powerful" while eye witnesses said the impact of the blast at the bus stop was such that interiors of two shops right behind it in a three-storied building were badly damaged.

DGP V Dinesh Reddy said it was "definitely the handiwork of a terrorist network" and IEDs were used in the attack.

Union Home Minister Sushil Kumar Shinde on Friday visited the twin bomb blasts site at Dilsukhnagar.

Shinde, who reached Hyderabad by a special flight this morning, drove straight to Dilsukhnagar and went around the blast site.

He said investigations have begun and the state government has appointed a probe team.

Replying to a query about inputs suggesting that a blast might take place in Hyderabad, the Home Minister said there was no specific alert and only a general alert was issued to the states.

To another query about the involvement of group in the blast, he said, "Such things can't be said at the moment".

The blasts triggered by IEDs took place outside a roadside eatery near Konark and Venkatadiri theatres in the area located on the Hyderabad-Vijaywada national highway in Cyberabad police limits.

The previous major attack in Hyderabad was on August 25, 2007 when two blasts took place almost simultaneously in which 42 people were killed. The first blast was in Lumbini amusement park followed by another at an eating joint.

In the same year, there was a blast at the famous Mecca Masjid in which nine people were killed.

The Dilsukhnagar area witnessed a blast in 2002 near a famous Saibaba temple in which two persons were killed and over 20 injured.