Suspected Maoists on Friday triggered a blast in an election office of the BJP at Hariharganj area of Palamu district, knocking down a part of its wall, a police officer said.

Nobody was present inside the election office during the incident, he said.

"Preliminary investigation suggests that armed rebels came on motorcycles around midnight, planted a bomb inside the party's office and triggered the blast," Chhatarpur Sub- divisional Police Officer Shambhu Kumar Singh said.

Several Maoist pamphlets, calling for poll boycott in the region, have been found lying at the blast site, he said.

Palamu district is a part of Palamu (SC) Lok Sabha constituency, which is set to go to polls on April 29, along with Lohardaga (ST) and Chatra seats.