Iranian Foreign Ministry Spokesman Ramin Mehmanparast blasted London for suppressing peaceful protests in the country, and urged Britain to show more tolerance and respect for democracy and freedom of expression, Fars News Agency reported.
Mehmanparast asked the British government to avoid violence against the British people's peaceful protests.
"The behavior of the British police towards people's peaceful demonstration on July 1 is yet another indication of (London's) opposition to the legitimate rights of the people to express their beliefs and have gatherings," he said.
"We ask the British government to respect the rights of the detainees and avoid any kind of violent action against the peaceful protests of the people who poured to the streets to defend their rights," the Iranian spokesman concluded.
The British police forces arrested 37 demonstrators as hundreds of thousands of people in different cities of Britain walked off the job to protest at pension cuts on Friday.
Airport operators warned there could be long lines at immigration entry points because of walkouts by passport officers on Thursday.
Unions estimated that up to 750,000 teachers and civil servants joined the one-day strike, which disrupted courthouses, tax offices, employment centers and schools.
Thousands of union members marched through London and other cities to demand that the government rethink plans to curb public-sector pensions.