Both Lok Janshakti Party chief Paswan and Rashtriya Janata Dal president Lalu Prasad were detained at the Dak Bungalow Crossing in the city along with hundreds of their party leaders and supporters, police said.

The Lok Janshakti Party chief demanded that the Nitish Kumar-led government be dismissed for being unable to check the collapse of law and order situation in the state.

Main opposition Rashtriya Janata Dal chief Lalu Prasad also raised slogans against the state government before police took him away.

Trains were blocked and trucks and buses remained off the roads in Bihar as the daylong shutdown came into effect Monday.

Workers of opposition parties blocked railway tracks and forcibly stopped trains at various stations to enforce the shutdown against the police firing in Madhubani Monday that also left over a dozen people injured. Trucks and buses too remained off the road in the state, police said.

The parties supporting the state-wide shutdown include the RJD, LJP, the Congress and the Nationalist Congress Party as well as the Communist Party of India (CPI), Communist Party of India-Marxist (CPI-M) and the Communist Party of India-Marxist-Leninist (CPI-ML).

"Several long route trains as well as passenger trains were stopped by bandh supporters and the road traffic was badly hit across the state," a police official said.

Trains were forcibly stopped at major railway stations like Patna, Gaya, Nalanda, Shekhpura, Jehanabad, Hajipur, Madhubani, Saharsa and Darbhanga, police said.

According to East Central Railway zone officials in Hajipur, about 20 km from here, thousands of passengers were stranded at various railway stations.

Workers of opposition parties blocked railway tracks in Nalanda, Gaya, Jehanabad, Darbhanga, Hajipur, Bhagalpur, Madhubani and Saharsa districts, disrupting train services, an official said.

Besides, traffic was disrupted on national and state highways at various places. In Patna, busy roads like Ashok Rajpath, Exhibition Road, Bailey Road and Fraser Road were blocked by those supporting the shutdown, police said. All private schools and colleges in the city remained closed in view of the strike.

Additional Director General (Police Headquarters) Ravinder Kumar said additional police forces were deployed in several areas to avoid any untoward incident during the shutdown.

According to police officials here, stray incidents of violence and protestors' clashes with police were reported from Bhagalpur, Madhubani and Muzaffarpur. "More than 200 leaders and workers of opposition parties have been arrested," a police official said.

Two youths were killed Friday and over a dozen people injured after police opened fire at an irate mob in Madhubani town. Another youth injured in police action Saturday died Sunday.

The town has been simmering since a headless body was found almost a fortnight ago. The family members of a missing youth, Prashant Kumar, claimed that the body was his and demanded that it be handed over to them -- but the police remained unrelenting.

Hundreds of people joined the family members in pressing the demand. But when police still refused to give in, the mob turned violent and indulged in violent protests Friday and Saturday.

Bihar Chief Minister Nitish Kumar has ordered a judicial inquiry into the incident and transferred the district magistrate and superintendent of police of Madhubani with immediate effect.