TEHRAN - PRESIDENT Mahmoud Ahmadinejad accused Barack Obama on Thursday of behaving like his predecessor towards Iran and said there was not much point in talking to Washington unless the US president apologised.

Mr Obama said on Tuesday he was 'appalled and outraged' by a post-election crackdown and Washington withdrew invitations to Iranian diplomats to attend Independence Day celebrations on July 4 - stalling efforts to improve ties with Tehran.

White House rejects Ahmadinejad accusations ============================== WASHINGTON - THE White House on Thursday accused President Mahmoud Ahamdinejad of trying to make Iran's political crisis 'about the United States' in a first reaction to his latest fiery speech. ... more

'Mr Obama made a mistake to say those things ... our question is why he fell into this trap and said things that previously (former president George W) Bush used to say,' the semi-official Fars News Agency quoted Ahmadinejad as saying.

'Do you want to speak with this tone? If that is your stance then what is left to talk about ... I hope you avoid interfering in Iran's affairs and express your regret in a way that the Iranian nation is informed of it,' he said.

The world's fifth biggest oil exporter has crushed anti-government protests, flooding the streets of Tehran with police and militia to quell the most widespread unrest since the 1979 Islamic revolution.

About 20 people have been killed in protests after Mr Ahmadinejad was re-elected in a disputed June 12 poll which opposition leader Mirhossein Mousavi says was rigged.

In what appeared to be further evidence of the government's determination to crush resistance, 70 professors were detained after meeting Mr Mousavi, his website said on Thursday.

Mr Mousavi said he was under pressure to stop challenging the election result and also complained about the closure of his Kalameh-ye Sabz daily newspaper and arrest of its staff.

The row over the election has exposed an unprecedented public rift in within Iran's ruling elite.

With street protests fading, analysts say the battle has moved off the street into a behind-the-scenes struggle which has divided the clerical establishment into two camps. -- REUTERS