By Sadeq Saba BBC Middle East analyst

Reformists in Iran have reacted angrily to a statement by the hardline Revolutionary Guards which accused them of paving the way for a military invasion of the country by the United States.

The head of the largest pro-reform faction in parliament, Rajabali Mazrouei, has condemned the remarks as irresponsible and accused the guards of siding with the conservative faction.

He said more than 90 MPs were planning to question the defence minister to explain why the soldiers were intervening in politics - a violation, he said, of the country's constitution.

In their strongly-worded statement issued on Saturday, the guards said they were committed to defending the Islamic revolution against what they termed foreign invaders and their internal allies.

'Infiltration'

The Revolutionary Guards are an elite armed force personally responsible to Iran's supreme leader, Ayatollah Khamenei.

The guards once accused President Khatami of creating chaos

The guards' criticism of the reformist faction in the Iranian leadership was very harsh indeed.

They accused supporters of President Mohammed Khatami - without naming them directly - of abandoning the principles of Islamic revolution and working to turn Iran into a secular state.

Their statement said the existence of such a tendency in the Islamic regime had encouraged Iran's arch-enemy - the US - to think of a military invasion of the country.

They warned that opponents of the Islamic state had infiltrated the regime and were now openly supporting subversion on the streets.

An influential pro-reform newspaper, Norouz, asked Ayatollah Khamenei to make it clear whether he approved the statement by the guards.

But the guards insisted in their statement that they had an ideological duty to defend the Islamic regime if it was threatened.

Three years ago, a group of guard commanders issued another strongly-worded statement, accusing President Khatami of creating chaos in the country by his reform programme.