NEW DELHI : Militants exploded a bomb Wednesday outside an Indian paramilitary headquarters in the restive northeastern state of Manipur killing two soldiers, a force spokesman said.

No group immediately claimed responsibility for the attack on the Border Security Force (BSF) base in the state capital of Imphal. But dozens of tribal, nationalist and small rebel groups operate in the remote region near the Myanmar border.

About a dozen paramilitaries were taking part in an operation to check roads outside the base when the improvised explosive device went off, a force spokesman told AFP.

“Two of our soldiers were killed in the IED blast. The area has been cordoned off and investigations are on,” the spokesman added. Two civilians were injured in the explosion.

Two paramilitaries were injured on Tuesday after militants hurled grenades at another base in the city.

The northeast region is home to dozens of outlawed groups whose demands range from greater autonomy to secession from India.

The United Liberation Front of Western South East Asia is based in Myanmar and its militants are active in most of India’s seven northeastern states.

It was blamed for a 2015 attack on an army convoy in Manipur that killed 20 soldiers, prompting India to carry out strikes against the rebels inside Myanmar.

Northeast India, linked to the rest of the country by a narrow land corridor, has seen more than six decades of ethnic and separatist unrest in which more than 50,000 people have been killed.

However, many groups have struck deals with Indian authorities in recent years.