A suicide bomber detonated an explosive device in Turkey’s capital Sunday, near the Interior Ministry building, killing himself and injuring two police officers.

Turkey’s interior minister said a second assailant was killed in a shootout with police, The Associated Press reported.

The blast occurred just hours before the parliament was set to re-open after a three-month recess with an address by Turkish President Recep Tayyip Erdogan.

It was not immediately clear who the assailants were.

No one has claimed responsibility for the assault.

Some information for this report came from The Associated Press.