Updated

Police said Wednesday they had killed a man suspected of masterminding the bombing of a passenger train that injured eight people this week in India.

An anti-terrorist police squad engaged the suspect in an 11-hour gunbattle overnight, after tracking him down at the home of a Muslim cleric in the city of Lucknow, according to senior police official A. Satish Ganesh in the northern state of Uttar Pradesh.

Ganesh identified the slain suspect as Saifullah, and said he was wanted in connection with Tuesday's train blast near Bhopal in the central Indian state of Madhya Pradesh.

Indian police on Tuesday arrested and questioned four suspects in Madhya Pradesh, leading to tips that drove police in Uttar Pradesh to arrest two more suspects in the city of Kanpur, about 80 kilometers (50 miles) southwest of Lucknow.

The suspects said they had been hired by a man called Saifullah, whom they said was a sympathizer of the Islamic State terror group and was hiding in a Muslim neighborhood in Lucknow.

Police said Saifullah refused to surrender and fired on them with an automatic weapon.

Ganesh said items recovered from the cleric's house included an Islamic State flag, six mobile phones and detailed sketches of railway stations in the cities of New Delhi, Lucknow, Agra and Bangalore.

The incident came amid state elections in Uttar Pradesh, the results of which are expected Saturday.