A former Afghan National Army soldier who left the army to join the Taliban was captured on Friday in eastern Nangarhar province, according to an Isaf statement Saturday.
A joint force of Afghan and Isaf troops found the "deserter" in Nangarhar's Khugyani district and arrested him, Isaf said. He had stolen equipment belonging to Afghan security forces "and was planning to attend Taliban bomb-making training in Pakistan".
The forces detained one other suspected insurgent during the operation, it said.
The news comes in the same week that saw two Afghan troops open fire on their foreign soldier partners, cementing concerns about an increase in armed Afghan forces switching sides.
An Afghan policeman killed three British troops in Helmand on Sunday while an Afghan soldier wounded five US soldiers on Tuesday.
Security forces also captured a leader of insurgent group Islamic Movement of Uzbekistan, two other insurgents leaders, and "several suspected insurgents" in the Kunduz district of eastern Kunduz province, Isaf said in the same statement.
The IMU leader is an explosives expert who specialises in making suicide and improvised explosive devices for use in attacks against Afghan and coalition forces in Kunduz, it said.
Meanwhile, another explosives specialist was captured in a joint Afghan and Nato troops operation in Zharay district of southern Kandahar province on Saturday.
Isaf said in the statement that the Taliban explosives specialist was responsible for coordinating and executing improvised explosive device attacks against the Afghan and Nato forces throughout the region.
In a separate statement released Friday night, Isaf said a foreign soldier died in southern Afghanistan as a result of a non-battle related injury.
It provided no further details, referring identification to the soldier's national authorities.
The soldier's death brings the number of coalition troops killed this year to 245.