Kabul, Afghanistan CNN  — 

At least eight people, including a district governor from Kunduz province, were killed and 12 others were wounded following a suicide bombing at a mosque in northeastern Afghanistan early Friday, a provincial official said.

The suicide bomber targeted a crowd of people who were attending prayers at a mosque in Dashte Archi district for a tribal elder who had died a day earlier, said Enayatullah Khaliq, a spokesman for the Kunduz governor.

Civilian casualties in Afghanistan increased 23% in the first six months of this year, the United Nations said in a report released at the end of July.