A second explosion went off Monday morning at a cattle market in the town of Maiduguri, which has long been wracked by violence related to the radical sect.

There were no casualties from that blast, police chief Mike Zuokumor said.

“The enemies of Nigeria are scaring people from coming out to vote,” Zuokumor said as election workers prepared for Tuesday’s gubernatorial poll. Officials already have delayed governor elections in two other northern states after violence following the April 16 presidential vote left at least 500 dead.

The radical group known as Boko Haram had released a statement earlier Sunday defending its string of deadly attacks on police and religious leaders in recent months.

“All the people that we are killing, including ward heads, politicians, the police and the army have erred, because they are associating themselves with the government in its effort to arrest our Muslim brothers and sabotage Islam,” the group said in its statement released Sunday.

While the presidential vote sparked deadly riots across northern Nigeria, Borno state has seen little violence directly related to the voting so far this month. The group did, however, claim responsibility earlier this year for killing Modu Fannami Gubio, the Borno state candidate of the All Nigeria People’s Party.