Mourners on a cold, barren hill outside Kabul wept Friday as they buried loved ones killed in a suicide attack targeting Shiites, the latest victims in one of the bloodiest years in the war-torn country.

At a Shiite cemetery spread over the hills dozens of men wearing heavy coats and blankets laid to rest victims, many of whom suffered severe burns in the explosion which killed more than 40 people in the capital a day earlier.

During one ceremony relatives stood shoulder to shoulder or crouched on the hard ground sobbing as the body of Mohammad Sharif Akhlaqi, a political science graduate, was lowered into a freshly dug grave.

"This is not the first and this won't be the last," a mullah overseeing the burial told the mourners, warning of more attacks against Shiites in Sunni-majority Afghanistan.

"Don't be asleep. Wake up! You should take care of yourselves because the government hasn't helped us," he implored them.

His plea echoed growing anger at the government in the wake of Thursday's bloodshed, in which multiple blasts by the Islamic State group at a pro-Iran Shiite cultural centre in Kabul also left more than 80 wounded.

"We are tired of insecurity in this country," a mourner at another funeral on Friday told Tolo News, giving the government an ultimatum.

"Either protect us or resign."

The frustration and grief comes at the end of a particularly deadly year for ordinary Afghans, with the number of civilian casualties on track to be one of the highest on record since the US invasion in 2001.

More than 8,000 civilians were killed or wounded in conflict-related violence in the first nine months of this year, according to data compiled by the UN Assistance Mission in Afghanistan.

Last year's civilian casualty toll of 11,418 was the highest for a single year since the UN began systematically documenting civilian deaths and injuries in 2009.

Since the withdrawal of foreign combat troops in 2014 Afghan security forces have struggled to beat back the resurgent Taliban, which is still responsible for the majority of the attacks and casualties across the country.

But IS, which was first designated a terrorist group in the region in 2015, is defying a US-led aerial bombing campaign to expand its presence beyond its stronghold in the eastern province of Nangarhar and into other regions.

That includes the capital, where it has claimed 14 attacks this year alone, including three in December, resulting in hundreds of casualties and helping to make the city one of the deadliest places for civilians in the country.

Among the more than 120 victims of Thursday's assault were students and journalists from the Afghan Voice Agency, an anti-IS media outlet located in the same building.

They were marking the 38th anniversary of the Soviet invasion of Afghanistan -- the event ushering the start of nearly four decades of continuous conflict in the country -- when the suicide attacker slipped into the room and blew himself up.