Clashes have broken out in Tehran between riot police and teachers protesting about low pay and conditions.

Hundreds of teachers had started a protest rally near the presidential offices in the Iranian capital when the police moved in to disperse them.

About a dozen people were arrested during the clashes, and police struck some of the teachers with batons. The demonstrators were dispersed after about two hours.

The clashes came just two days after President Mohammad Khatami set up a commission to investigate the complaints of the teachers, who have been protesting in their thousands in recent weeks for higher salaries and better conditions.

'Discrimination'

Some 10,000 teachers protested outside parliament in Tehran on Tuesday, despite a police ban.

Many of the country's two million teachers earn less than the equivalent of $150 a month, which they say is impossible to live on.

They also say that there are wide disparities and "discrimination" - particularly with regard to those who work in privileged areas and those who work in poorer districts.

The teachers have been threatening to observe a nationwide strike if their demands are not met.