KANDAHAR: Suicide attackers, an ambush and a remotely-controlled bomb killed up to 50 people across Afghanistan Tuesday in the bloodiest day for civilians this year, officials said.

The bloodshed came as the nation prepared to celebrate the end of the Muslim holy month of Ramadan, with many of the dead shopping in bazaars for Eid celebrations, police and local government officials said.

In the worst attack, three suicide bombers killed up to 36 people in the capital of Afghanistan's southwestern Nimroz province on the border with Iran.

Hours later in the northern province of Kunduz, a bomb attached to a motorcycle killed at least 10 people in the market of Archi district near the border with Tajikistan.

Then, in Badakhshan in the northeast, a district governor and four security personnel died in an ambush as they were driving to the provincial capital Faizabad, the provincial governor's spokesman Abdul Maroof Rasekh told AFP.

Taliban insurgents, who have waged a decade-long war to topple the Western-backed government of President Hamid Karzai, were blamed for the attacks.

The attack on Zaranj city, capital of Nimroz, was the biggest in recent memory in the relatively peaceful province and one of the deadliest anywhere in the war-torn country this year. At least 66 people were injured.

Three suicide attackers out of an original group of 11 blew themselves up in separate areas of the city, one outside a hospital, police said.

“This was a group of 11 attackers who wanted to conduct simultaneous attacks across the city,” deputy provincial police chief Mujibullah Latifi told AFP.

“Security forces killed two of the suicide attackers last night and detained three others this morning. Three managed to detonate themselves while three others were gunned down.

“We have a lot of civilian casualties because two of the attackers detonated themselves near a bazaar where many people had gathered to do shopping for Eid”, he said.

President Hamid Karzai condemned the “terrorist” attacks in Zaranj city, saying: “Attacks on Muslims while they are fasting are a sign of enmity with Islam.”

The violence across the country will add to growing concerns over Afghanistan's future once some 130,000 Nato troops withdraw as planned by the end of 2014, handing responsibility for security to Afghan forces.

Western politicians keen to get their troops out of an increasingly unpopular war regularly talk up the ability of the Afghan army and police to cope on their own, but there is widespread fear of Taliban gains and a multi-factional civil war once they leave.

Nato's International Security Assistance Force said last month that attacks in the second quarter of this year were 11 percent higher than in the same period last year.

The month of June alone saw the highest number of attacks in nearly two years, with more than 100 assaults a day across the country, including firefights and roadside bombings, the US-led coalition said. Civilians continue to bear the brunt of the war.

The United Nations said 1,145 Afghan non-combatants lost their lives, mostly in Taliban and other insurgent attacks in the first six months of this year. Last year, a record 3,021 civilians died.