A suicide car bomber killed two people and wounded dozens more outside a NATO-run training base on Friday, in an attack claimed by the Taliban to avenge the execution of its prisoners.
Several NATO soldiers were lightly wounded, a spokesman for the US-led International Security Assistance Force (ISAF) said, without giving further details.
Taliban claimed responsibility for the blast, saying it was to avenge the execution on Wednesday of four Taliban members who had been on death row in Kabul.
"It was a car bomb by our mujahed on a military training centre," Taliban spokesman Zabihullah Mujahid told AFP.
"It was a revenge attack by our mujahed in response to the execution of four mujahedeen by the Kabul administration."
A police spokesman said the blast was near "a joint coordination office for the Afghan army, police and NATO troops in Maidan Shar", the capital of Wardak province, some 50 kilomtres (30 miles) from Kabul.
"From this centre they go for military operations," Abdul Wali told AFP.
He said two people were killed and at least 40 were wounded, while the head of the Maidan Shar hospital said 90 people were brought to the hospital.
"We have 90 wounded, 75 men and 15 women. Two killed have also been brought to the hospital. The rest were taken to private hospitals," Ghulam Farooq Mukhlis told AFP.
The four executed Taliban members were among a total of 14 prisoners hanged over two days this week in rare mass executions.
The Taliban, who are leading an insurgency against the Western-backed government and 100,000 NATO troops, had warned there would be "heavy repercussions" for government officials if any of their militants were executed.
President Hamid Karzai approved the executions of the men who were sentenced to death "on charges of terror, conducting attacks, explosions and organising suicide attacks", the government said.
The executions were condemned by the United Nations, the European Union and human rights groups, with many pointing out that Afghanistan's justice system is notoriously weak.
The Taliban described the hanged men as "prisoners of war" and had called on the UN and rights groups to prevent their deaths.