A blast ripped through the backyard of the house of a relative of a Rashtriya Janata Dal member of Legislative Assembly in Bihar's East Champaran district on Monday.
Confusion prevailed over the number of casualties, if any, in the incident.
According to an official press release quoting District Magistrate Vinay Kumar, the explosion took place in the backyard of Sunil Kumar Singh, whose house adjoins his cousin, Dhaka MLA Manoj Kumar Singh's, at Balua village.
The release said a first information report has been lodged with the Patahi police station against Sunil Kumar Singh. It said raids were being conducted on the houses of all candidates in Dhaka constituency to recover illegal firearms and explosives that could be used to vitiate the polling on February 23.
The DM has also ordered the arrest of Sunil Kumar Singh within 24 hours.
The MLA himself could not be contacted despite repeated attempts.
Earlier, Patahi police station officer-in-charge Rampukar Singh told PTI that the explosions took place when alleged RJD activists were making bombs barely hours before the campaign for the third and last phase of the assembly polls in the state ended.
A police and Central Reserve Police Force team, which went to the spot, did not find any body, he said.
However, quoting eyewitnesses, he said three bodies had been lying in the backyard.