Attackers have opened fire at the Iranian parliament and Ayatollah Khomeini's mausoleum in the capital, Tehran, causing a number of casualties.
Heavy gunfire could be heard on videos filmed from outside parliament, and there are reports that a security guard has been killed.
Several people were injured in the attack at the mausoleum, dedicated to the founder of the Islamic Republic.
One suicide bomber and two or three other gunmen were involved. Reports are coming in of a second suicide bombing at the shrine.
The situation at the parliament remains confusing, with some reports of a suicide bomber there, and an an ongoing hostage situation - but the BBC cannot confirm these.
Fars news agency posted new pictures showing shooting around the building.
An image showing a man with a gun looking out of the window, initially described as an attacker by Iranian media, actually shows a policeman.
But MP Seyyed Hossein Naqavi-Hosseini told the Isna news agency that three gunmen were still in the building, in MPs' offices.
A photo posted by Fars showed people inside the parliament building lowering a child out of a first-floor window to people waiting below.
State TV news channel Irinn said seven or eight people had been injured at the parliament by four attackers.
The gunmen were carrying Kalashnikovs and one Colt pistol, reports said.
Irna said one gunman had been arrested.
The governor of Tehran said one attacker at the mausoleum had detonated a suicide vest and another had been killed by security forces, state broadcaster Irib reports.
Ali Khalili from the mausoleum's public relations office told the state-run Irna news agency that one of the armed men had blown himself up in front of a bank outside the mausoleum.
However, Fars reported that the suicide bomber was a woman. Images from the scene showed the remains of the bomber, apparently clad in black clothes.