Kabul - Afghan and international forces killed four suspected militants in two operations Saturday while an unknown number of rebels were killed by US-led coalition forces in a separate clash in the south, officials said.

Afghan security forces and NATO-led International Security Assistance Force (ISAF) troops conducted an operation in Deh-e-Manakah village of the Mohammed Agha district in the central province of Logar, the alliance said in a statement.

The combined forces killed three insurgents after giving them a chance to surrender, the statement said, adding that the operation was guided by information provided by local residents.

One rebel was killed and two were wounded when Afghan and ISAF troops targeted them in the Sabari district of the south-eastern province of Khost, an ISAF statement said.

The militants were planting a roadside bomb when they were spotted by an ISAF unmanned aircraft, the statement said. The wounded were detained and bomb-making materials were seized, it said.

An unknown number of suspected Taliban militants were killed Saturday in the Maiwand district of the south's Kandahar province, the US military said in a statement.

The coalition forces were fired upon when they reached a targeted compound, the statement said, adding that the troops called in air support when the barricaded militants did not come out of their bunker.

"Due to structural instability of the bunker, the force was unable to verify the number of militants killed but assessed that at least two armed combatants had engaged the force during the clash," the statement said.

About 70,000 international forces deployed from 42 nations are battling the Taliban, who have steadily gained power in the past three years after their ouster in a US-led invasion in late 2001.

Around 25,000 more international combat troops and military advisers were expected to arrive in Afghanistan before the country's presidential election in August. More than 20,000 of the new forces are to come from the United States and the rest from other ISAF troop-contributing countries. (dpa)