KABUL, Oct. 6 (Xinhua) -- Thirteen militants have been killed in separate incidents in two eastern Afghan provinces, the country's Defense Ministry said Saturday.

In one incident, nine Taliban militants were killed and three others wounded after Afghan army troops launched a cleanup operation in Andar district of Ghazni province on Friday, the ministry said in a statement.

On the same day, four militants of Islamic State (IS) militant group were killed after an Afghan Air Force-led airstrike struck an IS hideout in Khogyani district of neighboring Nangarhar province.

The violence has been on the rise as Afghan security forces struggle against a surge in attacks by militants at the time when the country is preparing for parliamentary and district councils elections slated for later this month.

During the Oct. 20 elections, nearly 9 million registered voters, including 3 million women, will cast their ballots to elect members of the 249-seat lower house of parliament for a five-year term while they will also vote to elect members of the district councils.