Ranchi, Jun 27 (IANS): Launching multiple attacks Tuesday night and early Wednesday, Maoists ambushed a police bus, blew up railway properties and a bridge at three different places in Jharkhand, police here said.

A policeman was killed and 12 others were injured when Maoist guerrillas ambushed their patrolling bus Tuesday night near the Topchachi police station of Dhanbad district, around 210 km from here.

All the injured were rushed to a nearby hospital where two were referred to the Apollo Hospital in Ranchi, a police spokesperson told IANS.

In another attack around 4.30 a.m. Wednesday, tracks were blown up and an engine was set on fire by Maoists at the Hehegara railway station in Latehar district, over 100 km from here, police said.

Railway tracks were also blown up early Wednesday between Taitulmuri and Nisitpur railway stations falling under the Dhanbad railway division, affecting regular services of over a dozen trains. Work has been started to restore the tracks, a railway official said.

In yet another attack early Wednesday, Maoists blew up a bridge near Chhatapur village in Giridih district, around 185 km from here. The bridge connects Giridih with Dhanbad.

The rebels have called a shutdown Wednesday in five states to protest the conviction of five Maoist guerrillas by a court in Uttar Pradesh. They are also pushing the government to stop an anti-Maoist operation popularly known as 'Operation Greenhunt.'

The shutdown has affected traffic and mining activities in the mineral-rich state.