"Four coalition service members were killed and two more were seriously wounded today in an IED (improvised explosive device) strike while conducting operations in Kandahar province," the statement said.
The nationalities of the soldiers was not revealed.
To the east, a Polish soldier from the separate Nato-led force died when a bomb hit his patrol shortly after midnight in the Dila district of Paktika province.
Jacek Poplawski, a Polish military spokesman in Warsaw, said four other soldiers were wounded, but their lives were not in danger.
The deadly attacks came a day after two other US-led soldiers were killed in separate incidents, including a suicide bombing elsewhere in the country.
Dozens of Taliban fighters were killed during the operation in Arghandab, a district near Kandahar city where about 500 Taliban gathered following a mass breakout from the city's main prison.
The latest deaths took to 32 the number of international soldiers killed in Afghanistan since the start of this month, the deadliest month for the foreign military deployment this year.
More than 20 soldiers died last month.
With the latest casualties, 99 foreign soldiers have died in Afghanistan this year, according to an AFP news agency tally based on official figures.