Both CNN and Al Jazeera are reporting an explosion at a mosque in Shiraz as of about 30 minutes ago, at 6 pm gmt+3.30.
Not a great deal of information is in at the moment, so updates will most likely follow.
UPDATE: It's now past midnight, GMT+1 in Stockholm, and at this point there is relatively no new information except a count of nine dead and 105 wounded.
I'll be turning in, but if anyone would like to monitor the situation further, perhaps one could begin an UPDATE comment and post beneath it.
Several dead in Iran mosque blast
Eight people have been killed and 50 others wounded in an explosion in the southern Iranian city of Shiraz, a national news agency has reported.
The explosion on Saturday was caused by "a powerful bomb at Shiraz's Mosque of the Martyrs after evening prayers," a report by Fars news agency said, citing city officials.
The death toll is expected to rise due to the severity of some people's injuries, officials have said.
Mohamed Hasan al-Bahrani, Al Jazeera's Tehran bureau chief, said that available information says that a bomb detonated in the mosque after Maghreb and Isha prayers.
The explosion took place in the section where males were praying, according to reports.
Fars said the force of the blast shook houses more than a kilometre away.
No group or individual has claimed responsibility for the explosion.
Fars reported that the mosque hosts weekly speeches about Wahaabism – a version of Sunni Islam - and the outlawed Bahai faith. Iran is a predominantly Shia country.
Last year, Bahai communities abroad said some of followers of the faith were detained in Shiraz while helping poor communities there.
Shiraz is close to a number of ancient sites popular with tourists.
The last major bombing in Iran occurred in the south-eastern city of Zahedan in February 2007.
Thirteen members of Iran's elite Revolutionary Guard died in that blast, with Sunni fighters blamed for the attack.
CNN now seems to offer a clarification from the Al Jazeera report:
The sermon denounced Bahai and Wahabi faiths, both of which are considered heresies by some Shiites.