Afghan and international forces killed or wounded more than 30 militants in fighting in the south and southeast of the country, the Defence Ministry and the U.S. military said on Thursday.
Violence has surged in Afghanistan with more than 2,500 people, including 1,000 civilians, killed in the conflict in the first six months of this year, according to aid agencies.
Afghan and international soldiers killed and wounded 18 insurgents in clashes in the district of Arghandab in the southern province of Zabul, the Defence Ministry said in a statement on Thursday.
"Twelve dead bodies of the insurgents were left on the battlefield," it said. Soldiers also found 10 kg (22 lbs) of opium left by the insurgents.
In a separate incident, Afghan soldiers killed 10 insurgents, including drug traffickers, during a security operation in Girishk district of southern Helmand province on Wednesday, the Defence Ministry said in another statement.
The incident was part of a larger operation aimed at clamping down on drug traffickers in the area. Helmand produces two-thirds of the country's opium, the raw ingredient of heroin.
Elsewhere, Afghan soldiers were engaged in fierce fighting with Taliban insurgents in Nad Ali district in another area of Helmand province.
"Heavy casualties were inflicted during fierce fighting between Afghan soldiers and insurgents, but the exact number of casualties is not known," the Defence Ministry said.
One soldier was killed and another wounded during the fighting, it said.
One soldier from the US-led coalition forces was killed while on patrol on Wednesday in southern Afghanistan, the US military said in a statement. It did not release the nationality of the dead soldier.
In southeastern Paktika province, US-led coalition forces killed one militant on Wednesday after he attacked the soldiers, the US military said in a separate statement.