'(The attack) was obviously carried out without the slightest regard for civilian life and achieved tragic levels of civilian casualties,' the NATO spokesman said.

According to NATO figures, the Kandahar blast raised the total number of civilians killed by the Afghan insurgency during this week alone to 55.

By contrast, the number of civilians killed by the Taliban during election week was 45.

The number of civilians injured by insurgents totalled 236 last week and 76 since Monday, NATO said.

Security operations by the alliance's International Security Assistance Force (ISAF) injured six civilians last week and none since Monday.

'I will continue to put into perspective the civilian casualties inflicted by other parties as opposed to ISAF,' Appathurai said.

This year has already become the deadliest for international forces operating in Afghanistan, with a total of 295 foreign soldiers killed to date, one more than 2008's total.