At least 11 people are known to have died after gunmen targeted civilians at a picnic spot in western Afghanistan.

Provincial officials originally said four people had been killed in the attack in the Enjil district of Herat province on Friday, but later said that seven more people who were critically injured had also died.

No group has claimed responsibility so far.

"Unidentified armed men" riding motorcycles opened fire near the village of Deh Mehri, an interior ministry spokesperson said. The recreational area is usually crowded on Fridays.

A Herat doctor told the BBC that the victims - who were Shia Muslims - had gone to a local shrine for a picnic. Shia Muslims are a minority group in Afghanistan and have been targeted in the past.

Ahmadullah Muttaqi, the provincial head of information and culture for the Taliban government in Herat, said the incident happened at about 15:00 local time (11:30 BST).

"In a terrorist incident, armed men opened fire on residents who had gone to Deh Mehri village in Enjil district for recreation," he told the BBC.

Muttaqi said four bodies, as well as 15 wounded people - including two women - were taken to the Herat regional hospital.

A suspect had been arrested by security forces, he said.

The village where the attack took place in is a predominantly Shiite village and has a Shiite Muslim shrine that many people visit daily to visit and pray, interior ministry spokesman Abdul Mateen Qani said

Correction: An earlier version of this story said the victims were from the Hazara ethnic group, but this is now believed not to be the case.