An explosion in a Shia mosque in the western Afghan city of Herat killed at least 29 people and wounded many others, police have said.

Abdulhai Walizada, a local police spokesman, said there appeared to be more than one attacker, with a suicide bomber who detonated explosives and another who threw grenades at worshippers.

A further 64 people were reportedly wounded during the attack at the Jawadia Mosque and local authorities said the death toll is expected to rise.

At Herat Main Hospital, Dr Mohammed Rafique Shehrzai said as many as 20 bodies were brought to the hospital in Herat city, the capital of western Herat province.

But Mehdi Hadid, a lawmaker from Herat, who went to the site soon after the explosion, said there could be "at least 100 dead" as he estimated hundreds of people had either been killed or wounded.

The attack took place in the middle of evening prayers when the mosque was packed with about 300 worshippers.

He said he rushed to the mosque after hearing about the explosion and was told the attacker first fired on the private guards outside the mosque before entering.

When inside, he fired on the praying worshippers until his rifle jammed then he blew himself up, Mr Hadid said.

Afghanistan: Between Hope and Fear Show all 16 1 /16 Afghanistan: Between Hope and Fear Afghanistan: Between Hope and Fear 2001 Afghans at the Killi Faizo refugee camp desperately reach for bags of rice being handed out to the thousands who escaped the bombardment in southern Afghanistan during Operation Enduring Freedom. (Chaman, Pakistan, December 4, 2001) Paula Bronstein Afghanistan: Between Hope and Fear 2002 Mahbooba stands against a bullet-ridden wall, waiting to be seen at a medical clinic. The seven-year-old girl suffers from leishmaniasis, a parasitical infection. (Kabul, March 1, 2002) All photos Paula Bronstein Afghanistan: Between Hope and Fear 2003 A mother and her two children look out from their cave dwelling. Many families who, fleeing the Taliban, took refuge inside caves adjacent to Bamiyan’s destroyed ancient Buddha statues now have nowhere else to live. (Bamiyan, November 19, 2003) Paula Bronstein Afghanistan: Between Hope and Fear 2007 Students recite prayers in a makeshift outdoor classroom in the Wakhan Corridor, a mountainous region in northeastern Afghanistan that extends to China and separates Tajikistan from India and Pakistan. (Northeastern Afghanistan, September 2, 2007) Paula Bronstein Afghanistan: Between Hope and Fear 2007 Bodybuilders in the 55-60 kg category square off during a regional bodybuilding competition. Many Afghan men, like others around the world, feel that a macho image of physical strength is important. (Kabul, August 6, 2007) Paula Bronstein Afghanistan: Between Hope and Fear 2008 A woman in a white burqa enjoys an afternoon with her family feeding the white pigeons at the Blue Mosque. (Mazar-e-Sharif, March 8, 2008) Paula Bronstein Afghanistan: Between Hope and Fear 2009 Addicts inject heroin while trying to keep warm inside the abandoned Russian Cultural Center, which the capital city’s addicts use as a common gathering point. Heroin is readily available, costing about one dollar a hit. (Kabul, February 9, 2009) Paula Bronstein Afghanistan: Between Hope and Fear 2009 An elderly man holds his granddaughter in their tent at a refugee camp after they were forced to flee their village, which US and NATO forces had bombed because, they claimed, it was a Taliban hideout. (Surobi, Nangarhar Province, February 7, 2009) Paula Bronstein Afghanistan: Between Hope and Fear 2009 Seven-year-old Attiullah, a patient at Mirwais Hospital, stands alongside an X ray showing the bullet that entered his back, nearly killing him. Attiullah was shot by US forces when he was caught in a crossfire as he was herding sheep. (Kandahar, October 13, 2009). Paula Bronstein Afghanistan: Between Hope and Fear 2010 US Army Sargeant Jay Kenney (right), with Task Force Destiny, helps wounded Afghan National Army soldiers exit a Blackhawk helicopter after they have been rescued in an air mission. (Kandahar, December 12, 2010) Paula Bronstein Afghanistan: Between Hope and Fear 2010 An Afghan National Army battalion marches back to barracks at the Kabul Military Training Center. (Kabul, October 4, 2010) Paula Bronstein Afghanistan: Between Hope and Fear 2014 Eid Muhammad, seventy, lives in a house with a view overlooking the hills of Kabul. He and millions of other Afghans occupy land and housing without possessing formal deeds to them. (Kabul, November 21, 2014) Paula Bronstein Afghanistan: Between Hope and Fear 2014 Razima holds her two-year-old son, Malik, while waiting for medical attention at the Boost Hospital emergency room. (Lashkar Gah, Helmand Province, June 23, 2014) Paula Bronstein Afghanistan: Between Hope and Fear 2014 Young women cheer as they attend a rally for the Afghan presidential candidate Ashraf Ghani. (Kabul, April 1, 2014) Paula Bronstein Afghanistan: Between Hope and Fear 2014 Burqa-clad women wait to vote after a polling station runs out of ballots. (Kabul, April 5, 2014) Paula Bronstein Afghanistan: Between Hope and Fear 2015 Relatives, friends, and women’s rights activists grieve at the home of Farkhunda Malikzada, who was killed by a mob in the center of Kabul. Farkhunda was violently beaten and set on fire after a local cleric accused her of burning a Qur’an. (Kabul, March 22, 2015) Paula Bronstein

Shia Muslims are a minority in Afghanistan and have been threatened by the Isis affiliate, which operates in the country's east.

There was no immediate claim of responsibility for the latest attack to hit Afghanistan, which has seen more than 1,700 civilian deaths so far this year.

Afghanistan has traditionally been relatively free of the sectarian violence common in Iraq or Syria but hardline Sunni militants from the local branch of Isis have repeatedly attacked the mainly Shia Hazara minority in the past year.

Herat, which is close to the border with Shia-majority Iran, is considered to be one of the most peaceful cities in Afghanistan.