Afghan and NATO troops targeted a group of Taliban fighters in southern Afghanistan, killing 17 militants and wounding six others, the Defense Ministry said on Monday.
Four police were killed separately in a militant ambush in central Ghazni province, a provincial official said.
The joint force clashed with militants in the Marjah district of Helmand province on Sunday, the ministry said in a statement.
The troops recovered militants' weapons and ammunition and 132 pounds (60 kilograms) of drugs after the clash, it said. Southern Afghanistan is the center of the Taliban-led insurgency that this year has claimed more than 2,700 lives in Afghanistan, according to an Associated Press tally of figures provided by Afghan and Western officials.
Helmand province is also the world's largest opium poppy-growing region, the main ingredient in heroin. Western officials say some of the proceeds from the multibillion dollar trade go to fund the Taliban. Government officials are also believed to be involved in the illicit trade.
Also on Sunday, militants ambushed a two-vehicle police convoy in Ghazni's Zana Khan district, killing four officers and wounding seven, said Sayed Ismail Jahangir, a spokesman for the provincial governor.
Separately, the U.S.-led coalition said its troops killed several militants and captured one they had sought in the northern Baghlan province on Sunday. The troops were searching for a militant wanted in connection with planting roadside bombs.
A coalition statement on Monday did not specify the number of militants killed.