A bomb planted in a mosque in a southeastern Iranian city near the border with Pakistan and Afghanistan has reportedly caused civilian casualties.

At least twenty people have been killed in the bombing in the city of Zahedan while more than fifty five others have been injured, the Fars news agency reported.

The crowd had gathered at the mosque to commemorate the death anniversary of the daughter of the prophet of Islam.

Aid groups and medics have rushed to the scene. The mosque has been partially destroyed by the blast.

Scores of people have also been affected by the shockwaves.

No group or individual has claimed responsibility. Within minutes of the blast, a second explosive was defused at the mosque.

MT/AA