DELHI, India (CNN) -- India is on high alert after a series of near-simultaneous explosions killed at least 50 people and wounded 150 others in the northwestern city of Jaipur Tuesday night, government and local officials told CNN-IBN.

The seven explosions started at about 7:30 p.m. (1400 GMT, 1000 ET) and detonated within 12 minutes of each other, police said.

The bombs exploded within about 500 meters (0.3 mile) of each other in Jaipur's old city, which is frequented by tourists. See the aftermath of the explosions. »