AHMEDABAD/MUMBAI: As the death toll from the serial blasts, now counted at 19, crept up to 49, Ahmedabad woke up to an edgy start on Sunday with police defusing an unexploded bomb at Hatkeshwar in Maninagar, where the first terror bomb had gone off. ( Watch )

Although the fears of a backlash to the bombings remained unfounded, the state administration, eager to avoid fresh turmoil, called the Army onto the streets to stage flag marches in several parts of the city. (In Pics: Blasts rock Ahmedabad)

As with previous serial blasts, whether in Jaipur or Varanasi, investigators made no initial headway, despite hopes pinned on the recovery from Surat of two cars packed with material to make bombs. Police officers said that the cars could yield vital clues.

Until then, the obvious parallels were being drawn with the May 13 Jaipur blasts in which the vehicles of death were the ubiquitous "aam admi" mode of transport - bicycles.

Also, police further locked into the Jaipur connection because the table clocks used in the Jaipur blasts were similar to the ones used as timers on Saturday.

That tied in with the burden of suspicion falling on SIMI, which intelligence experts now say has strong ties with Bangladesh-based Harkat-ul-Jihad al-Islami and Al-Qaida-linked Lashkar-e-Toiba.

Police say the scale of Saturday's attacks would have needed a network of more than 50 terrorists, something only a SIMI-HuJI combine could deliver.

Police also suspect ammonium nitrate and LPG bottles were used for maximum impact in the two bombs which went off at LG Hospital and Civil Hospital.

Police say 5kg LPG cylinders were strapped along with the ammonium nitrate mix to create greater heat and power.

At LG Hospital, a portion of a wall was blown off and more than 20 people died at the Civil Hospital alone.

Meanwhile, the city crime branch on Sunday confirmed the arrest of a person named Abdul Halim from Dani Limda area in the heart of the city. ( Watch )

Halim, also wanted in the 2002 Gujarat riots case, had gone into hiding after the sectarian violence and remained untraceable. Police said Halim belongs to the Ahl-e-Hadees group and is a native of Uttar Pradesh, settled in Ahmedabad since the 1980s.

He was booked in the RDX haul case in Delhi in which Shahid Bakshi and Farhan were convicted. Joint commissioner of police (crime) Ashish Bhatia said the arrest could provide leads in the blast.

"There were reports that he was hiding in Delhi and we had intimated Delhi police as well. After receiving some specific inputs about his whereabouts, the crime branch arrested him during a combing operation," Bhatia said.

Halim was wanted for enticing disgruntled youths from refugee camps for riot victims in and around Ahmedabad and taking them to Uttar Pradesh. "From there, an organized network was engaged in sending these youths across the border to Pakistan for training. Halim was part of this network," said Bhatia.

Also, the live bomb found in Hatkeshwar on Sunday could provide clues on the architects of Saturday���s attacks.

Police say in this case, the terrorists used old cycles, unlike in Jaipur where new bikes had been bought on the morning of the blasts. The Hatkeshwar bomb had ammonium nitrate, ball bearings for shrapnel and was packed in an oval container with a steel lid.

A timer device was fixed to trigger it. Late Saturday evening, a bomb found on an Ahmedabad Municipal Transport Service bus in Gandhinagar was defused.

Eleven bodies were yet to be identified at hospitals. State held an emergency meeting and formed a panel headed by principal secretary (home) Balwant Singh to coordinate intelligence inputs from other states and the Centre.