A Shiite mosque in western Afghanistan was stormed during evening prayers Tuesday, torn asunder by grenades and a suicide bomber's detonated vest, law enforcement officials say. By the time the scene had settled at the place of worship, at least 29 people were killed and dozens more were injured.

And local officials say the death toll could still rise.

"Two attackers entered the mosque and started shooting and throwing grenades at people," worshipper Mohammad Adi, who was hospitalized for his wounds after the assault, tells Reuters.

"Based on our initial information two terrorists were involved, one of them wearing a suicide vest who detonated himself while the second one was armed with a rifle," local police spokesman Abdul Ahad Walizada tells the news agency Agence-France Presse. "They are both dead."

No group immediately claimed responsibility for the attack, which unfolded at the Jawadia mosque in the city of Herat, near Afghanistan's border with Iran. Both news services note the Taliban has denied involvement in the violence.

The Associated Press describes the aftermath of the attack:

"[Local lawmaker Mehdi] Hadid said he saw several pieces of a body that was being identified as the assailant. Although it's not clear if there was a second attacker, witnesses in the area reported hearing a second explosion about 10 minutes after the initial bomber detonated his explosives."The mosque was badly damaged with windows blown out, walls and even the large dome peppered with shrapnel and everywhere was blood from the victims, said Hadid."Located just 50 meters (150 feet) away was an Afghan National Police station, but Hadid said the police were too frightened to take action and stood outside the mosque while the attack happened."

The violence follows on the heels of another deadly attack in Afghanistan, this one launched Monday on the Iraqi Embassy in Kabul. As NPR's Scott Neuman reported, witnesses described an embassy building that was racked with gunfire and several explosions.

Reuters notes that so far this year, more than 1,700 civilians have been killed in Afghanistan. The persistent violence has at times attracted protests from Afghans fed up with what they see as the government's failure to maintain its citizens' safety.

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