A sound bomb detonated near the Evangelical Church in Upper Egypt's Minya city late Sunday, state news agency MENA reported.
No casualties or damage has been reported.
Police and explosives experts arrived at the site to investigate the incident and installed a security cordon.
Egypt has been witnessing a security insurgency over the past year with explosions usually targeting police and military sites.
However, sectarian tensions have been rife in Minya, home to a large Coptic community who make up at least 10 percent of the entire Egyptian population.
Following the forcible dispersal of two Islamist sit-ins in August 2013 that left hundreds dead and sparked a wave of violence nationwide, around 11 churches were attacked in Minya alone.