A suspected suicide bomber killed at least 14 people in Afghanistan on Saturday and fighting between militants and security forces left at least 36 people dead on the first day of Ramazan.

In eastern Khost province, an attacker detonated a car bomb near a soccer field that is close to a military base, officials said.

At a local hospital, doctors received at least 14 dead bodies and eight wounded people, said Gul Mohammaddin Mangal, head of the public health department in Khost.

"The bodies are not recognisable and it is hard to say if they are civilians or security forces," he said.

In the north-western province of Badghis, militants attacked security forces in Qadis district, sparking fighting that killed 22 insurgents, six security forces, and eight civilians, said Zahir Bahand a spokesman for the provincial governor.

The fighting also left 33 militants and 17 civilians wounded, he said.

The Western-backed Afghan government is battling both Taliban and Islamic State militants around the country.

Taliban forces have increased their attacks in the weeks before Ramasan, with a string of strikes in Kandahar, Paktia, and Helmand, among other provinces.

Muslims around the world typically mark Ramazan with fasting, prayers, and other observances, although the holy month can begin on different days in different countries.