Suspected militants set off two bombs outside a police station in India's restive northeast on Sunday, killing seven people and wounding more than 50, police said.

Five people died instantly after two blasts went off within minutes of each other outside the station in Nalbari town near the Assam state capital, Gauhati, a local police official said. Two people died later in a hospital, he said.

The official, speaking on condition of anonymity as he is not authorized to speak to the media, said what officials had earlier reported was a third bomb in a market a few miles away, turned out to be a firecracker.

At least 52 people were wounded in the two blasts, said Bhaskar Mahanta, Assam's inspector general of police.

India's northeast is beset by scores of conflicts. More than 10,000 people have died in separatist violence over the past decade. The region is home to dozens of separatist groups that accuse the government of exploiting the area's natural resources while doing little for the indigenous people.

Mahanta said authorities suspect the militant separatist group United Liberation Front of Asom is behind the blasts. No group claimed responsibility.

The bombers had parked two bicycles fitted with carriers packed with explosives outside the Nalbari police station, which is located in a congested part of the town, Mahanta said. These went off, killing passers-by and wounding the others.

Mahanta said police had received intelligence reports suggesting that the ULFA was planning to avenge last week's arrest of two of the group's leaders.

Last week, suspected ULFA rebels triggered a powerful explosion, derailing a freight train and setting more than a dozen oil tanker railcars on fire in Assam.

The ULFA has spurned the Indian government's offer to hold talks with them on condition that the group give up violence.