"The Iranian police detained a correspondent and operator of RT Arabic when they filmed a report in the vicinity of parliament," the broadcaster said.
Earlier in the day, the group of four people in women's clothes opened fire in the building of the Iranian Parliament, with a subsequent explosion. Another attack involving an explosion took place near the Imam Khomeini shrine.
The Iranian Justice Ministry said earlier in the day that at least 12 people were killed and 39 injured in the attacks on the parliament and the Imam Khomeini shrine, also in Tehran.
Daesh claimed responsibility for the attacks.