May 14 (Bloomberg) -- Indian police blamed terrorists for blasts that killed as many as 60 people in the northern city of Jaipur in the nation's deadliest attack in more than a year.

``It is a terrorist plot, it is obvious,'' said A.S. Gill, director general of police.

Authorities imposed a curfew in 15 regions of the city after nine bombs placed on parked bicycles injured more than 100 yesterday. While the police are bringing people in for questioning, no arrests have been made, Sriniwas Rao, Inspector General of Police, said by phone.

The attacks are the worst since 68 people were killed on a cross-border train running from the capital, New Delhi, to Lahore in neighboring Pakistan in February 2007. India's federal government has stepped up security across the nation, with a ``high alert'' being declared in cities including New Delhi and Mumbai, Junior Home Minister Sriprakash Jaiswal said.

``The kind of material used, the structure of the explosives and the way it was used, is not the work of any ordinary person,'' said Gulab Chand Kataria, Rajasthan home minister. Royal demolition explosive, known as RDX, was packed with pellets, he said. ``Experts must be involved.''

The government previously blamed terrorist attacks on organizations linked to foreign powers, without offering evidence or making arrests. Few of the attacks are owned up to, with most newspapers and televisions channels accusing groups backed by Pakistan or Bangladesh without identifying the security officials who provided the information.

Foreign Hand

Three hours after the blasts Minister Jaiswal said terrorists with foreign links had carried out the attacks. He didn't provide details.

The federal government dispatched a team of investigators to assist with the probe, the home ministry said today.

``The priority is to quickly identify the culprits and apprehend them at the earliest,'' the home ministry said in a statement. ``The home ministry has issued advisories to all the states to heighten the alert.''

India has held Muslim Kashmiri separatist groups responsible for previous attacks, including one on parliament in 1991. India has repeatedly asked the government in Islamabad to prevent extremists crossing the border to carry out attacks. Pakistan has denied the allegation, saying it only lends moral support to a freedom struggle in the disputed Himalayan territory of Kashmir.

Pakistan's Prime Minister Yousuf Raza Gilani condemned yesterday's attacks.

``Pakistan condemns all acts of terrorism and reaffirms its firm commitment to fight this scourge together with the international community,'' said Gilani, who was elected in March.

Mangled Bicycles

Television pictures from Jaipur showed pools of blood that stained the streets, shopping bags strewn around and mangled bicycles at the scene of the blasts. The Indian Express newspaper carried a photo of a man slumped in the backseat of a cycle rickshaw on its front page today.

Harkut-ul Jihad al Islami, a group based in Bangladesh, is suspected of being behind the attack, state-run broadcaster Doordarshan cited unidentified Home Ministry officials as saying.

The police is investigating these claims, Rajasthan minister Kataria said. The police defused one device, he said.

``We have not got any major leads,'' H.G. Raghavendra Suhasa, a superintendent of police of Jaipur city, said by phone.

President Pratibha Patil and Prime Minister Manmohan Singh condemned the attacks. ``She has appealed for peace and calm,'' the president's office said in a statement. The prime minister pledged assistance to the state government in Rajasthan and the victims' families, his office said.

`No Justification'

``There is no justification for the murder of innocent people,'' the U.S. State Department said in a statement from Washington yesterday. The U.S. stands with India in the fight to ``eliminate the scourge of terrorism,'' it said.

The attacks may dent India's efforts to promote the world's second-most populous nation as a tourist destination as Jaipur forms the western leg of the so-called Golden Triangle that includes New Delhi and Agra, home to the Taj Mahal.

The blasts occurred near the city's main tourist attraction, the 18th Century Palace of the Winds, or Hawa Mahal. This is the off-peak season for tourism, when summer temperatures may reach at least 40 degrees Celsius (104 degrees Fahrenheit).

Improved Ties

The two sides have improved relations since coming close to a fourth war in 2002. Train bombings in Mumbai in July 2006 that killed 184 people caused a temporary stoppage in the peace process. As many as 257 people were killed in 1993 bombings in Mumbai, which India says were carried out by associates of organized crime figure Dawood Ibrahim.

India says its neighbor is harboring Ibrahim, an accusation that Pakistan denies.

Terrorists from Pakistan and Bangladesh are collaborating to carry out attacks in India using the Bangladeshi border as a crossing point, A.K. Mitra, director general of India's Border Security Force, said in December. India handed Bangladesh a list of 141 militants and criminals it wants detained when the countries held security talks in Dhaka last November.

Near simultaneous blasts in three cities in India's most populous state, Uttar Pradesh, killed at least 13 people and injured 61 others in a coordinated attack on the nation's justice system in November.

To contact the reporters on this story: M.C. Govardhana Rangan in Mumbai at grangan@bloomberg.net; Bibhudatta Pradhan in New Delhi at bpradhan@bloomberg.net.

Last Updated: May 14, 2008 04:54 EDT