Five members of the Iranian security services have been arrested in connection with the death of a Iranian-Canadian journalist earlier this month.
The Canadian-Iranian journalist died after being arrested in Tehran
Zahra Kazemi, 54, died in hospital in Tehran on 10 July, two weeks after receiving head injuries following more than three days of interrogation.
She had been taking photographs outside a prison when she was arrested.
An Iranian report said she died in custody from a severe blow to the head which fractured her skull and caused a brain haemorrhage.
The five officers were arrested on Saturday following "comprehensive investigations" into her death, state-run radio reported.
They have not been named, and Iran has not said which agencies they work for.
On Wednesday, Canada condemned the burial of the journalist in Iran - which was apparently against her family's wishes - and said it was recalling its ambassador from Tehran and considering sanctions.
Amid the tensions between the two countries, Iran summoned Canada's charge d'affaires in Tehran to protest against the shooting death of an Iranian teenager in Canada.
An Iranian foreign ministry spokesman has demanded that Canada "give an explicit, transparent and satisfactory explanation" of the shooting dead of Keyvan Tabesh, 18, near Vancouver on 14 July.
Canada's Foreign Minister, Bill Graham, has promised a full and transparent investigation into the shooting by a police officer.
He urged Iran to do the same in connection with the death of Kazemi.
On Friday, Iran appointed senior judge Javad Esmaeili to lead a new investigation into her death.
The father of the Iranian teenager told Canada's Globe and Mail newspaper that the shooting of his son was "not racist".
"My son had blue eyes. He had a European face, like he was from England or Spain, not Iran," Nasser Tabesh told the newspaper.
"The bullet that shot into my son's heart was shot at a Canadian teenager, not at someone from Iran," he said.
Tabesh, an Iranian citizen, had been living in Canada about two years.
The journalist's burial in Iran has sparked anger in Canada
Iran defended the decision to bury Kazemi in the city of Shiraz on Wednesday, saying they had the go-ahead from her mother.
But Kazemi's son, Montreal-based Stephan Hachemi, has said his 75-year-old grandmother was "forced" to authorise the burial.
Canada backed Mr Hachemi's calls for her body to be returned to Canada for a post-mortem and burial.