By Biswajyoti Das DISPUR, India, Jan 8 (Reuters) - Thousands of poor migrant labourers in India's remote northeast will be moved to government shelters on Monday after dozens were massacred at the weekend by a powerful rebel group, authorities said. Separatist militants have killed 69 migrants in a spate of attacks across Assam state since Friday in the worst violence in the troubled region in years, forcing authorities to deploy hundreds of new soldiers and policemen, and step up security. Hundreds of migrant labourers, mostly from the eastern state of Bihar, have panicked after the wave of attacks and are fleeing Assam in trains, officials and witnesses said. Hundreds more, some of them carrying the bodies of victims, continued to block roads for the second day in Doomdooma town, about 500 km (310 miles) east of Assam's main city of Guwahati, demanding action against the insurgents. "We have decided to bring all labourers working in brick kilns to a designated place during nights and they are escorted by police to their work sites during the day," Himanta Biswa Sarma, a senior Assam minister and the government's spokesman, told reporters. Most victims worked at brick kilns which were now being guarded by police, he said. The attacks have been blamed on the United Liberation Front of Asom (ULFA), which has been fighting for the independence of Assamese people in a conflict that has killed thousands of people since it began almost three decades ago. Last week the ULFA warned non-Assamese businessmen and labourers of dire consequences if they continued to live in Assam, accusing New Delhi of flooding the state with outsiders to reduce the indigenous Assamese population to a minority. Security forces fear the rebels could launch attacks elsewhere in coming days and Sarma said the militants seemed to have an edge for now as they had the capacity to spring surprises. "Security forces have started night domination and patrolling all over the state to thwart further rebel attacks on innocent civilians," the minister said. "The security forces have become active because we can't read the mind of the militants and they may have some other gameplan now," he added. Hundreds of troops have been raiding insurgent hideouts in the jungles and killed two insurgents in one overnight gun battle, officials said. The pair were suspected of being part of a group involved in the killing of nine people in the eastern district of Sivasagar on Sunday, they said. Many other rebels had fled to the mountains of the neighbouring Arunachal Pradesh state, they added. Violence has surged in Assam since the ULFA walked out of peace talks with the central government in September after New Delhi called off a truce saying the rebels had violated it. Security analysts said that, with the attacks, the ULFA had sent a message to New Delhi that it was still a force to be reckoned with.