Story highlights India reaching out to neighboring nations for assistance as it pursues militants

"The army is going out with full intensity," an Indian military spokesman tells CNN

At least 72 people were killed in the assault by Bodo militants on Tuesday

Home minister has ruled out talks with outfits indulging in "cold-blooded murder"

Army, paramilitary and police troops have intensified counter-insurgency operations in Assam in the wake of Tuesday's tribal militant raid, which left at least 72 people killed in India's remote tea-producing state, a defense spokesman said.

"The army is going out with full intensity," Lt. Col. Suneet Newton, an Indian military spokesman from Assam, told CNN Friday. Army-led joint operations have been scaled up in all troubled districts of the state, including Kokrahar and Sonitpur, where Bodo extremists carried out a series of deadly attacks on other tribal communities earlier this week, Newton said.

Meantime, federal authorities have despatched 5,000 additional armed police to Assam, according to state Inspector General S.N. Singh.

Separately, three people died when police fired at violent mobs trying to storm a police station in Sonitpur district on Wednesday, Singh told CNN.

On Thursday, Indian Home Minister Rajnath Singh termed the militant strike in Assam a "massacre" as he vowed to pursue what he called a "time-bound action against terror." He also ruled out talks with outfits indulging in "cold-blooded murder," according to a home ministry statement.

As part of anti-insurgent efforts in Assam, India said it was also reaching out to its eastern neighbors for assistance. India's seven northeastern states are wedged between China, Bhutan, Myanmar and Bangladesh, and reports have emerged that Bodo militants might be hiding out beyond Indian territory.

Sushma Swaraj, India's external-affairs minister, already has contacted the Bhutanese leadership "at the highest level," spokesman Syed Akbaruddin told reporters in New Delhi.

"We are also working on having contacts with others who could possibly help us in this matter. Once that is completed, I will share those details with you," Akbaruddin said.

India's impoverished northeast region, where Assam is located, has a high concentration of extremist groups from different backgrounds with conflicting ethnic and political interests.

Members of the Bodo tribe, an indigenous group, have fought for decades for political autonomy. They also have long-standing tensions with Muslim settlers in Assam. But on Tuesday they attacked members of non-Assamese tribal people who have lived in the state since before India got independence in 1947, Inspector General S.N. Singh said.