PATNA, Nov 1(PTI): An estimated 23% voters cast their votes till noon in 42 assembly constituencies in Bihar on Monday where Maoists triggered a blast in Betia forest and unidentified persons set off four explosions in Danapur.

23% of the voters had exercised their franchise till 12 pm.

Director General of Police Neelmani said Maoists had triggered a blast near a bridge on the Chakai-Jamui main road in Betia jungle, but none was injured.

Around 38 people have been arrested from various constituencies, Neelmani said, adding 39 vehicles were also seized.

In another incident, unidentified persons set off four bombs near booth Nos. 56 and 57 in Danapur, but none was injured, police sources said.

Defects in EVMs were initially reported from some booths in Bhagalpur and Banka districts, but were promptly attended to, official sources said.

Meanwhile, FIRs were lodged against RJD chief Lalu Prasad and his wife Rabri Devi for entering a booth here to cast their votes with securitymen in tow in violation of the model code of conduct. (Read: FIR against Lalu, Rabri)

The FIRs were registered by Block Development Officer of Digha Ashok Kumar with the Patna airport police station, sub-divisional magistrate-cum-Returning Officer for Digha assembly constituency Maqsood Alam said.

The couple were accompanied by son Tejpratap and daughter Ragini.

Around 10.04 crore voters are eligible to exercise their franchise to decide the fate of 568 candidates, including 58 women in the fourth phase of polling in Bihar.

Voting is being held in Maoist hit areas of Alauli (SC), Suryagarha, Tarapur, Jamalpur, Katoria (SC), Belhar, Sinkandra (SC), Jamui, Jhajha, Teghra, Bachwara and Chakai between 7:00 am and 3:00 pm.

Prominent contestants include BJP stalwarts and ministers Ashwini Kumar Choubey (Bhagalpur), Nand Kishore Yadav (Patna Sahib) Ramnarayan Mandal (Banka), besides JD(U) minister Damodar Raut.