US President Barack Obama has criticized the Iranian government's response to street rallies but rejected that US was instigating the protests.

In a Tuesday news conference, Obama said he was 'appalled and outraged' by 'threats, beatings and imprisonments of the last few days'.

"I strongly condemn these unjust actions," he added.

Despite an official ban by Iranian authorities on any gathering, supporters of presidential candidate Mir-Hossein Mousavi staged daily rallies in capital Tehran to protest at result of presidential election, in which incumbent Mahmoud Ahmadinejad was re-elected with almost two thirds of votes.

Some of the protests have turned violent, resulting in the death of at least 20 people.

Iran says it's police have not shot any protestors during the rallies, adding that it arrested the saboteurs who had vandalized public property and disturb the public peace during the rallies.

Obama dismissed accusations that the US was instigating massive protests as 'patently false and absurd'.

Last week, Iran summoned the Swiss ambassador, who represents US interests in Tehran, to protest at US interference in Iran's internal affairs.

AKM/AKM