At least 35 people, including seven NATO soldiers, were killed in a string of roadside bombs and clashes on Sunday, one of the most violent days in the country for months.

A bomb killed six NATO troops in the east, the coalition said without elaborating, after a Taliban attack in the south killed one foreign soldier.

Twenty-eight Afghan civilians and police were killed in southern Kandahar and Helmand provinces, officials said.

The Taliban said early on Sunday that a roadside bomb had killed four American soldiers in eastern Logar province, where Czech soldiers are based. The exact location of the six dead NATO soldiers in the east was not immediately clear.

Taliban in a brief statement said “At least four invaders were killed Sunday in clash with Mujahideen of the Islamic Emirate unfolding in Baraki Barak district, Logar province after Mujahideen attacked their foot patrol”. The statement added: “At least 7 invaders were killed Saturday in two separate attacks by Mujahideen of the Islamic Emirate targeting the enemy’s army Camp and combat patrol in Yaqoobi district of Khost province”.

The death brings the number of foreign troops to 228 so far this year in the Afghan war, according to icasualties.org which tracks the number of foreign troops killed in Afghanistan.

In southern Kandahar province, the birthplace of the Taliban where the group has substantial sway and enjoys popular support, three bombs hit three vehicles, killing 18 people mostly civilians.

According to the Mine Action Coordination Center of Afghanistan, the last estimate was that 5,550 mines and explosives still posed a "hazard" in the country.

Its latest figures for mine clearance show 8,261 explosives were cleared during May. About 4,752 of these were anti-personnel mines.

Two policemen were killed by a bomb to the west of Kandahar in southern Helmand province, where clashes with militants killed a further four officers, the Helmand media office said.

Civilians bear the brunt of the violence. Although the U.N. reported a 20 percent decrease in civilian deaths in the first four months of this year from the same period in 2011, last year saw the number of civilians killed in Afghanistan rise for a fifth straight year to over 3,000.

NATO says the vast majority of these deaths are caused by Taliban while Taliban accuses NATO-led forces for civilian deaths.

Meanwhile the head of Ghazni province’s attorney general office was shot dead by unknown gunmen on Monday morning while he was on his way to his office, said an official.

Unidentified gunmen opened fire at the victim, Sahar Gol, at about 8.30 am while he was travelling to his office. Police said and the attackers managed to flee the scene and police had launched a search for the killers. Police added.

A school girl was also injured in the shooting incident.

Taliban spokesperson Zabiullah Mujahid said the movement took responsibility for the killing.

According to Pajhwok News Agency reports quoting an eye witness Ata Mohammad that three men sitting in a Corolla car fired at the victim and speed off.