The Afghan government says 19 civilians have been killed in a roadside bomb attack in southern Afghanistan, bringing the death toll to 78 in two turbulent days of violence.
Mohammad Ismail, provincial security force commander, said a minivan was hit by the bomb while travelling through Helmand province on Wednesday, and that women and children were among the dead.
"Nineteen people including seven women and five children have been killed in today's IED [improvised explosive device] attack," said Ismail. "The seven women are from the same family."
Ismail added that five others were wounded and being treated at a NATO base.
The blasts came as the civilians travelled from provincial capital Lashkar Gah to Sangin district, historically one of the most troubled in Afghanistan.
Parts of Helmand remain highly unstable although Lashkar Gah is under the control of Afghan forces and three other districts are due to transition from NATO to Afghan security control within weeks.
The deaths came the day after 59 people died in two blasts at Shia shrines.
At least 55 people were killed in a blast in Kabul on Tuesday while commemorating the Shia holy day of Ashoura. A second near-simultaneous strike killed four people and injured 21 in the northern city of Mazar-e-Sharif as a convoy of Shia Muslims was driving past.
It was not immediately clear who carried out the attacks but suspicion centred on Sunni armed groups based in neighbouring Pakistan.
Afghan President Hamid Karzai, who cancelled a visit to the UK to return home on Wednesday, blamed the attacks on enemies of the state.
"Without any doubt, the enemies of Afghanistan are trying to separate the Afghan people," President Hamid Karzai said.
In a statement on Wednesday, Karzai named the Pakistan-based Lashkar-e-Jhangvi as the group behind yesterday's attacks in Kabul and Mazar-e-Sharif.
"We will investigate the issue very carefully and will discuss it with the Pakistani government," Karzai said in Kabul.
Reporting from Kabul, Al Jazeera's Jennifer Glasse said Karzai's statements against Lashkar-e-Jhangvi, who have never carried out an attack in Afghanistan in the past, "won't do anything to improve relations between Afghanistan and Pakistan."
Our correspondent said that while at a burial ceremony in a Kabul cemetery on Wednesday, people accused Pakistan of having a hand in Tuesday's attacks.
The group, said to be linked to al-Qaeda, previously claimed responsibility for an October bus attack in Pakistan that led to the deaths of at least 13 Shia Muslims headed to a vegetable market.
Until now, the decade-long Afghan war has largely been spared sectarian violence.
Both the Taliban and the United States have condemned the attacks.