A roadside bomb exploded next to an Afghan army vehicle, killing all six soldiers on board, while a separate bomb and gunfire attack left two Nato soldiers wounded.
In eastern Paktia province on Saturday, a roadside bomb hit a patrol vehicle, killing six Afghan soldiers who were working with American troops, said provincial police chief General Abdul Anan Roufi.
Insurgents ambushed the Nato troops in southern Zabul province, wounding two soldiers and damaging four vehicles with a roadside bomb and gunfire, said Captain Andre Salloum, a spokesman for Nato's troops in the south.
The southern and eastern regions of Afghanistan have seen a huge increase in violence this year. Taliban militants have conducted a record number of suicide and roadside bombings, and close to 4,000 people have died in insurgency related violence.
The Defence Ministry, meanwhile, said Afghan and coalition troops on Friday arrested 13 terror suspects in Kandahar province. General Zahar Azimi said the 13 had come from Pakistan.
``The enemy were gathered to do some terrorist action, but we received reports of them and we captured them,'' said Azimi.
The suspects were handed over to the US-led coalition for further investigation, Azimi said.
Afghan and Western officials say that Pakistan does not do enough to stem the flow of terrorists who cross the border from neighbouring Pakistan to wreak havoc in Afghanistan. Pakistan denies the charge, saying it does all that it can.