The Union home ministry sounded a nation-wide alert on Tuesday night following the serial bomb blasts in Jaipur killing over 15 and injuring more than 100 people.

"The home ministry is keeping a close watch on the situation in the Pink City," a senior MHA official said, adding that an alert has been sounded in all states.

Senior officials, including Home Secretary Madhukar Gupta, immediately got in touch with the state government and asked them to beef up security arrangements.

Terrorists set off six bomb blasts at crowded markets in the Walled City within a span of ten minutes killing and wounding several people.

MHA spokesman said Home Minister Shivraj Patil, who was on a two-day visit to Northeast, condemned the blasts. He was also in touch with his ministry officials.

A bomb data squad of the elite National Security Guards has been rushed to the Jaipur.