Late Tuesday, police said 29 people had been killed and 64 wounded in the western city of Herat. Both attackers are dead, a police spokesperson told the French news agency AFP.

The assault took place at about 8 pm (1530 UTC) at the Jawadya mosque in Herat, which is close to Afghanistan's border with Iran.

"The death toll has risen to 29 killed and 63 wounded. Some wounded are in a critical condition so the toll may go up," hospital spokesman Rafeeq Shirzai told AFP.

Witnesses said one of the men detonated explosives and at least one other, a gunman, threw grenades at worshippers. IRIB, the state broadcaster in neighboring Iran, said seven gunmen had been involved. 

"The mosque was full of people when the incident happened," Abdul Ahad Walizada, spokesman for Herat police, told the German news agency DPA.

There has been no claim of responsibility so far, with the Taliban spokesman Zabihullah Mujahid tweeting: "Bomb blast in Jawadiyah mosque in Herat has nothing to do with the mujahedeen." The Taliban controls about 11 percent of the country.

On heels of IS attack

The attack comes a day after an assault on the Iraqi embassy in Kabul, which was claimed by the Islamic State (IS), killed two people.

But experts have previously questioned whether there are direct links between the group's local affiliate Islamic State Khorasan Province (IS-K) and the central IS command.

Insecurity on the rise 

Tuesday's attack in Herat is likely to hit confidence in the Western-backed government of President Ashraf Ghani, whose government has been under pressure because of deteriorating security.

The US administration is considering sending more troops to Afghanistan to bolster the NATO-led coalition advising and assisting Afghan security forces.

Ghani condemned the bombing and called on religious scholars to "raise their voices against the terrorist attacks." Ghani added that "terrorists cannot create sectarian divisions among our people."

The capital Kabul alone has witnessed 11 large attacks since January, with over 1,000 people dead or injured. The attacks have been conducted by IS and the Taliban.

Sectarian violence

The Herat attack was the latest in a series of assaults on Afghanistan's minority Shiite population.

Shiites, of which there are around three million in Afghanistan, have regularly been targeted in recent years.

Afghanistan has traditionally been relatively free of sectarian violence, but hardline Sunni militants from the local branch of IS have attacked the mainly Shiite Hazara minority in the past year.

jbh/jr (AFP, Reuters, dpa)