Soon after President A P J Abdul Kalam accepted the Centre's recommendation to dissolve the assembly in Bihar, the state was put on high alert on Monday.
Official sources in state home department said forces, including central paramilitary, Rapid Action Force and state police personnel, were deployed in Patna and also in other parts of the state in view of likely protests.
The newly appointed advisor to Governor Buta Singh directed all district magistrates and superintendents of police to maintain law and order and take necessary action against troublemakers.
The government had on Sunday requested the central home ministry for extra forces.
The state Chief Secretary K A H Subramanian said deployment of forces was needed to maintain law and order in the state.
Police had already tightened security in and around Raj Bhawan on Sunday following the order of Singh, officials said.
The Bharatiya Janata Party and Janata Dal-United leaders in Bihar have threatened to launch agitations against the Centre. "We will go to the people and not sit silently," said state BJP president Gopal Narain Singh.