Fifteen people, mostly students, were killed in the insurgency-racked Indian state of Assam Sunday when a bomb exploded in a college ground during independence day celebrations, a police officer said.

Several outlawed groups fighting Indian rule in the oil and tea-rich state had called for a boycott of the independence celebrations, saying it was a black day.

Several people were injured in the explosion that took place shortly before a flag hoisting ceremony in the college ground in remote Dhemaji district of Assam, police said.

"Suddenly there was an explosion. Most of the victims were students who were participating in the parade," police inspector general Khagen Sharma said, adding 15 people were killed.

India's northeast is home to dozens of insurgent groups, some demanding more autonomy and others secession. The groups accuse New Delhi of plundering the region's rich resources and flooding it with outsiders.

India's celebrates its independence from British colonial rule in 1947 with colorful parades and flag hoisting ceremonies across the nation of more than a billion people.

Source: CD/Agencies