At least 14 people have been killed in an attack on a shrine in the Afghan capital, Kabul as Shia Muslims prepared for a religious day of mourning.
A crowd had gathered at the Karte Sakhi shrine for Ashura, a commemoration of the martyrdom of Hussein, a grandson of the Prophet Muhammad.
No group has claimed responsibility.
Meanwhile, hundreds of Afghan troops have been deployed to drive Taliban fighters from the capital of Helmand province, Lashkar Gah, in the south.
Militants have been pushed back to the outskirts of Lashkar Gah, a strategically important city, local officials told the BBC.
Lashkar Gah is reportedly in lock down with only a few shops open and many families trying to flee the fighting.
Schools and universities across Helmand have been closed indefinitely.
The new assault is the Taliban's most concerted push yet into the city.
The attack in Kabul happened in one of the city's largest shrines.
One of the dead was a police officer, a spokesperson for the Ministry of the Interior said.
Sediq Sediqqi said police special forces who responded to the scene found and killed only one gunman. Initial reports said three attackers were involved.
An eyewitness said the attacker was dressed in a police uniform.
The government had warned of possible attacks during the day.
An attack in July, claimed by so-called Islamic State, killed 80 people, but before then Afghanistan had not seen the same level of violence against Shia Muslims as neighbouring Pakistan.
Shia Muslims make up about 15% of Afghanistan's population, and many of them come from the Hazara ethnic group.