According security sources, a suicide bomber detonated his explosive vest inside the Mosque shortly after the Friday prayers.
No terror group has claimed responsibility but Islamic State terrorists have often been linked with such attacks.
The heinous attack targeting Muslim faithful at a Mosque has received condemnation from across religious divide.
The news of the Shia Mosque explosion comes only a day after a series of bomb explosions and shooting attack at residential neighborhood in and around Baghdad that left eight people killed and two dozen others injured.
Northern and western parts of Iraq have been faced by gruesome violence ever since Islamic State terrorists launched an offensive in June 2014, and taking control of portions of the Iraqi territory.
Islamic State terrorists have been committing vicious crimes against all ethnic and religious communities in Iraq, including Shias, Sunnis, Kurds, and Christians.
Iraqi army soldiers and fighters from allied Popular Mobilization Units are battling the terrorists seeking to win back militant-held regions in joint operations.