KHOST, Afghanistan, June 7 (Xinhua) -- Four civilians have been killed and five others wounded after gunmen fired on worshippers at a mosque in Afghanistan's eastern province of Khost, a provincial government spokesman said Thursday.

The firing took place in Kamal Khil Mosque in Lalmayi locality, Mandozayi district on Wednesday evening after gunmen entered the mosque and fired onto people who were offering evening prayers, spokesman Talib Mangal told Xinhua.

The assailants fled the scene shortly after the shooting and police have launched an investigation into the case, he added.

The motive behind the attack remained unknown and no group has claimed responsibility for the incident yet.

The Afghan civilians continue to bear the brunt of armed conflicts as more than 3,430 civilians were killed and over 7,000 others injured in conflict-related incidents in 2017, according to figures of the United Nations mission in the country.?