Four people were killed and 35 wounded after a suicide bomber detonated a car packed with explosives at a bus station in Potiskum, a town in northeast Nigeria, on Sunday.

Although no one immediately claimed responsibility for the blast, investigators believe Jihadist group Boko Haram are the most likely culprits, reports Reuters.

“The information I have is that the car was pretending to be scouting for passengers,” Yobe state police commissioner Danladi Marcus told the news agency.

Nigeria is seeing spiraling violence ahead of general elections pitting incumbent President Goodluck Jonathan against former junta chief Muhammadu Buhari. The polls are considered the closest contest since military rule ended in 1999.

[Reuters]

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Charlie Campbell at charlie.campbell@time.com.