UNITED NATIONS, May 6 (Xinhua) -- UN Secretary-General Antonio Guterres has strongly condemned the attack on a mosque being used as a voter registration center in Khost province of Afghanistan, his spokesperson said on Sunday.

Guterres extends his deepest condolences to the families of the victims and wishes a speedy recovery to those injured, said Stephane Dujarric.

The UN chief extends his solidarity to Afghan citizens seeking to exercise their constitutional rights and take part in the forthcoming parliamentary elections, Dujarric added.

The bombing in the eastern Afghan province killed at least 14 people and wounded 33, local officials said on Sunday.

A spokesman for the provincial governor said the blast happened while some people were busy with prayers while others had gathered to get their voter registration cards for the elections.

Afghanistan plans to hold elections in October, the first since 2014.