WASHINGTON (Reuters) - The White House condemned on Sunday what it called the “unjust suppression” of civilians by the Iranian government and said the United States was on the side of protesters.

Four people died in Tehran on Sunday when pro-reform protesters clashed with security forces, Iranian state TV said, in the worst outbreak of violence since June’s disputed presidential election sparked political turmoil.

“We strongly condemn the violent and unjust suppression of civilians in Iran seeking to exercise their universal rights,” White House National Security Council spokesman Mike Hammer said in a statement.

“Hope and history are on the side of those who peacefully seek their universal rights, and so is the United States,” Hammer said.

“Governing through fear and violence is never just, and as President (Barack) Obama said in Oslo -- it is telling when governments fear the aspirations of their own people more than the power of any other nation,” Hammer said in a reference to Obama’s speech this month accepting the Nobel Peace Prize.

Iranian opposition websites said eight people were killed as tens of thousands demonstrated across Iran during the Shi’ite Muslim Tasoua and Ashura festival on December 26-27.

It was the first time people had died in street protests against Iran’s clerical leadership since the immediate aftermath of the presidential election in which the opposition says more than 70 people were killed.

The unrest that erupted after that June vote is the biggest in the Islamic state’s 30-year history. Authorities deny opposition charges that the voting was rigged.

The turmoil has complicated the international dispute over Iran’s nuclear program, which the West believes may have military ends and Iran denies. Tehran has rejected the year-end deadline set by Washington and other world powers to agree to a U.N.-drafted deal to ship most of its low-enriched uranium abroad in exchange for fuel for a research reactor.