"After intelligence agencies alerted us that Maoists are likely to attack these places in their strongholds, their security has been tightened," Additional Director General of Police Ravinder Kumar said.
According to police, the likely targets could be prisons in Patna, Muzaffarpur and Bhagalpur districts.
Security has been tightened in prisons and police stations in Bihar.
Dozens of Maoists, including senior leaders, are lodged in Patna's Beur Jail and in the central jails in Bhagalpur and Muzaffarpur.
"Maoists may target these prisons to free their members," said a police official.
Similarly, all police stations located near jails have also been put on high alert after intelligence reports cited the alleged attack plans of the outlawed Communist Party of India-Maoist.
Bihar saw a major jailbreak in November 2005 when as many as 380 prisoners fled from the Jehanabad prison. Later, nearly 300 returned to the jail or were re-arrested.