Iran's foreign ministry said on Monday that the arrests of citizens linked to the United Kingdom showed London's "destructive role" in the recent protests in Iran.
Asked by a reporter to comment on Sunday's announcement in Tehran of the arrest of seven people linked to Britain, foreign ministry spokesperson Nasser Kanaani said: "Some countries, especially the one you mentioned, had an unconstructive role regarding the recent developments in Iran.
"Their role was totally destructive and incited the riots."
Iran's Revolutionary Guards said on Sunday that the seven, including some who held dual nationality, were arrested over anti-government protests that have rocked the country.
The British foreign ministry had said it was seeking further information from Iranian authorities on the reports that British-Iranian dual nationals had been arrested.
Kanaani said Tehran had notified the detainees' respective governments and had "communicated their crimes" to them.
For "humanitarian reasons," he said, the detainees had been allowed to contact their families over the Christmas holidays.
Tehran has blamed foreign enemies and their agents for orchestrating the protests, which have turned into a popular revolt by Iranians from all layers of society, posing one of the boldest challenges to the country's clerical rulers since the 1979 revolution.
It has also taken increasingly aggressive steps against dual nationals, arresting dozens since the unrest began. Such moves have brought more international condemnation and isolated the Islamic Republic.
Rights group HRANA said that as of Sunday, 507 protesters had been killed, including 69 minors. It said 66 members of the security forces had also been killed. As many as 18,516 protesters are believed to have been arrested, it said.
Kanaani said the files of some of the detainees had been completed, while those of others were still being investigated.