Egypt’s government sacked nearly 700 top police officers Wednesday, state television reported, the start of a promised cleansing of a force blamed for chronic abuses during the rule of Hosni Mubarak.

The move meets a key demand of protesters encamped in Cairo’s Tahrir Square who are frustrated by the slow pace of change since an 18-day uprising forced the long-entrenched president from office in February.

In another overture to protesters, Egypt’s state news agency reported that parliamentary elections, which had been slated for September, would be postponed by a month or two. That decision is likely to be welcomed by the burgeoning political parties that emerged from the uprising who worried that an early vote would make it difficult for them to compete with established groups like the Muslim Brotherhood.

Protesters have called for the Interior Ministry to be restructured and purged of officers and Mubarak loyalists involved in the killing of nearly 900 protesters during the uprising. So far, just one person — a noncommissioned police officer who was sentenced to death in absentia — has been convicted for the killing of protesters.

The Mubarak-era interior minister, Habib al-Adli, has yet to stand trial for his alleged role in the deaths of protesters, but he has been convicted on fraud charges. Mubarak and his two sons, Gamal and Alaa, are scheduled to go on trial in August on graft charges and allegations linking them to the killing of protesters.

Mansour el-Eissawy, the current interior minister, fired 669 officers — 505 major generals, 82 brigadier generals and 82 colonels — on Wednesday, state television reported, just a fraction of the estimated 33,000 police officers who report to the Interior Ministry. Of those fired, at least 27 face charges related to killing protesters, state television reported.

Human right groups have criticized Egypt’s interim leadership, a council of top military leaders, for the slow pace of trials of police officers and for allowing officers who are under investigation to stay on the job.

One of the main gripes of many Egyptians is that while police and Mubarak-era officials still have not been tried for the killings, more than 7,000 people have been convicted on charges such as stealing and breaking curfew in hasty military tribunals.

The police and election announcements came as authorities scrambled to mollify protesters, some of whom are calling for the resignation of Prime Minister Essam Sharaf.

Egypt’s military leadership effectively announced the postponement on Tuesday, when it said that preparations for the vote would start Sept. 30.

Many protesters welcomed the dismissal of the police officers, but wanted to see a wider purge, and demanded that those fired would not continue being paid.

“We need to make sure the right people are going out of service,” said Lilian Wagdy, an activist and blogger camped out in Tahrir Square.

Wagdy and many others argue that, despite Mubarak’s ouster, the backbone of his government is still in place through state media, the judiciary and the security apparatuses.

“We’re staying put until we see real concessions,” Wagdy said. “We want the remnants of the old regime to fall and to start building a new state.”

An Egyptian human rights group says it has found evidence of police officers intimidating families of slain protesters and injured people to force them to drop their complaints. The group, the Egyptian Initiative for Personal Rights, has called for the immediate suspension of police officers under investigation for the killing of protesters, and on Wednesday, Eissawy also announced that 54 lower-ranking officers under investigation had been reassigned so they do not interact with the public.