Guwahati: Police in Assam fired on Wednesday on demonstrators protesting against the killings of dozens of people by tribal guerrillas, killing five of them.

Militants fighting for a separate homeland for indigenous Bodo community went on a killing spree in Assam on Tuesday, killing 70 people in four attacks, the deadliest violence in months.

The victims of the guerrilla attacks were mostly tea-plantation workers from other parts of India.

Hundreds of plantation workers armed with spears and bows and arrows defied a curfew imposed in response to the rebel attacks and surrounded police stations in Sonitpur district, the area worst hit by the militant violence, saying authorities had failed to protect them.

Read: Centre rushes 5,000 paramilitary personnel to Assam

Some protesters set fire to shops and others blocked a railway line and roads. Police said they had to disperse the crowds.

"They were trying to storm police stations, we had to open fire as a result," a police officer from the area said by telephone.

Prime Minister Narendra Modi has vowed to accelerate the development of roads and railways but one of his ministers said the violence had to stop first.

"There can no development until there is peace," Minister of State for Home Kiren Rijiju told reporters, vowing to crush the militants.

Read: Arunachal Pradesh sounds high alert after Assam violence

The Tuesday attacks on plantation workers were blamed on a faction of the National Democratic Front of Bodoland in retaliation for an offensive against them launched by security forces a month ago.

Villagers told police the rebels came on foot, armed with assault rifles and wearing military uniforms.

"The militants first came and asked for water. Suddenly they opened fire with their AK-47 rifles,” a witness, who fled into jungle, later told reporters.