Expressing outrage over the serial blasts that ripped through the capital's busy markets on Saturday evening, President A P J Abdul Kalam and Prime Minister Manmohan Singh [Images] asserted that efforts to spread chaos would not succeed at any cost.

Expressing deep shock and grief over the loss of lives and grievous injuries caused to innocent civilians in the blasts, the prime minister said, "Efforts to spread chaos and disturb peace will not be allowed to succeed at any cost."

Blasts certainly not accident: Patil

After being informed about the blasts upon his arrival at Kolkata from Agartala, Dr Singh said the target of the attack were clearly the "innocent citizens." But he requested all sections of society to remain calm and extend fullest cooperation to the security agencies.

The prime minister, who cut short his visit to West Bengal, said the government was determined to defeat the nefarious designs of terrorist elements.

 Delhi blasts criminal act: Pakistan

"The perpetrators of these heinous acts will be dealt with firmly. The security agencies are already working in this regard," he said.

Dr Singh also expressed heart-felt condolences to the next of kin of those killed in the blasts.

Dr Kalam, in his message, appealed to the people to maintain calm and help in relief and rescue works.

 Red alert in capital, borders sealed

The President also spoke to Home Minister Shivraj Patil and Delhi Chief Minister Sheila Dikshit and took stock of the situation and relief work being undertaken by the authorities.

Meanwhile, Dr Singh has cancelled his visit to Kolkata and is rushing back to the capital.