At least 16 people were killed in bomb blasts in two Afghan cities on Thursday -- attacks claimed by the Islamic State group (IS).
Since Taliban fighters seized control of Afghanistan last year after ousting the US-backed government, the number of bombings has fallen but the jihadist and Sunni IS has continued with attacks -- often against Shiite targets.
Earlier this week, at least six people were killed in twin blasts that hit a boys' school in a Shiite neighbourhood of Kabul.
On Thursday, 12 worshippers were killed in a blast at a Shiite mosque in the northern city of Mazar-i-Sharif, said Ahmad Zia Zindani, spokesman for the provincial public health department in Balkh.
He added that 58 people were wounded, including 32 in serious condition.
Grisly images posted to social media showed victims of the attack at Seh Dokan mosque being transported to hospital.
"Blood and fear are everywhere," Zindani told AFP, adding "people were screaming" while seeking news of their relatives at the hospital.
"Many residents were also coming to donate blood," he said.
The blast occurred as worshippers were offering midday prayers during the Muslim holy month of Ramadan.
In a statement, the IS group said "the soldiers of the caliphate managed to get a booby-trapped bag" inside the mosque, detonating it remotely.
In a separate blast in the city of Kunduz, at least four people were killed and 18 others wounded. Police spokesman Obaidullah Abedi said a bicycle bomb exploded near a vehicle carrying mechanics working for the Taliban.
Late on Thursday, IS claimed that attack as well, but said its fighters set off an explosive device on a bus carrying Kunduz airport employees.
Taliban authorities vowed to punish those responsible for the bloodshed.
"Soon the culprits of these crimes will be found and punished harshly," government spokesman Zabihullah Mujahid said on Twitter.
- 'Religious, ethnic hostility' -
Shiite Afghans, who are mostly from the Hazara community that makes up between 10 and 20 percent of Afghanistan's population of 38 million, have long been the target of the IS, who consider them heretics.
"There is religious and ethnic hostility towards the Shiites and Hazaras in particular," said prominent Shiite leader Mohammad Mohaqqiq.
"All extremist groups that are in Afghanistan, be it IS or even Taliban, have shown this hostility."
State Department spokesman Ned Price said the United States condemned the attacks "in the strongest terms."
"We are committed to supporting the ability of all Afghans, including religious minorities, to practice their religion freely without fear of violence against them," Price told reporters.
"We're extremely concerned about the recent rise of violence in Afghanistan and call for an end to these cowardly attacks and for the perpetrators to be brought to justice."
No group has yet to claim the deadly attack on a boys' school in Kabul on Tuesday, which also wounded more than 25.
"Systematic targeted attacks on crowded schools & mosques call for immediate investigation, accountability and end to such human rights violations," tweeted Richard Bennett, the United Nations Special Rapporteur for Afghanistan on human rights.
Taliban officials insist their forces have defeated IS, but analysts say the jihadist group is a key security challenge.
Since seizing power, the Taliban have regularly raided suspected IS hideouts in eastern Nangarhar province.
In May last year, at least 85 people -- mainly female students -- were killed and about 300 wounded when three bombs exploded near their school in the Shiite dominated Dasht-e-Barchi neighbourhood of Kabul.
No group claimed responsibility for that, but in October 2020 IS admitted a suicide attack on an educational centre in the same area that killed 24 people, including students.
In May 2020, the group was blamed for a bloody attack on a maternity ward of a hospital in the same neighbourhood that killed 25 people, including new mothers.