Thousands of Egyptians have braved scorching heat to rally in Cairo's Tahrir Square, where they are pressing the interim government to speed up the pace of reforms.

Some activists taking part in Friday's protests have camped in the square for a week.

However, western news reports say the Muslim Brotherhood – Egypt's best organized political group – is not taking part in the rally, deciding for now to work in the background on reforms.

The protests come after the Interior Ministry announced the dismissals of more than 600 police officers on Wednesday.

The move was an apparent bid to meet the demands of demonstrators who have called for swifter justice for those involved in crimes under former President Hosni Mubarak's leadership.

The government also announced a delay of up to two months in parliamentary elections that had been scheduled for September. Secular and liberal activists had said they needed more time to prepare candidates.