Egypt’s infamous emergency law, which had given President Hosni Mubarak and his police forces vast authority to crack down on dissent, expired Thursday, and officials said they were disinclined to extend it.

Suspension of the law, which had been in effect for more than 30 years, was among the key demands of revolutionaries who toppled Mubarak on Feb. 11, 2011. Human rights activists hailed its expiration as a historic milestone and among the most important dividends of last year’s popular revolt.

“It’s a law that symbolized the extraordinary powers given to the police, which created an environment in which forced disappearances and torture happened regularly,” said Heba Morayef, a Cairo-based researcher for Human Rights Watch.

The expiration of the law means in theory that detainees held under its provisions should have been released by the end of the day on Thursday, Morayef said. But the researcher said her group had confirmed that at least 188 people who were picked up under the emergency law remained in custody.

Egypt’s military council, which assumed power after Mubarak was forced to step down, vowed Thursday to continue maintaining security, saying in a statement issued to the state news agency that it “affirms to the great people of Egypt that it continues bearing this responsibility.”

In Washington, State Department spokesman Mark Toner told reporters that the United States had “repeatedly encouraged” the generals to lift the law, and he called its expiration a step toward the country’s democratic transition.

The generals made no mention in their statement of seeking an extension to the law, a step that would require parliamentary approval.

Farid Ismail, the deputy head of the defense and national security committee in parliament, said that the military chiefs had not asked that the law be kept in place, and that lawmakers would be unlikely to sign off on such a request.

“There is no willingness to extend the state of emergency law,” said Ismail, a member of the dominant group in parliament, the Muslim Brotherhood’s Freedom and Justice Party.

The Brotherhood, a venerable Islamist organization, was among the opposition groups in the country that suffered most from the law. Many of the organization’s leaders were imprisoned for years, without due process, based on the government’s contention that they posed a security threat.

The expiration of the law does not mark the end of the state security tactics that human rights activists call heavy-handed. The military, for example, retains the authority to prosecute civilians in military tribunals.

The military had issued an amended version of the emergency law in September, when protesters attacked the Israeli Embassy in Cairo. In February, it had said that it was going to keep a scaled-down version of the law that would allow authorities to detain people suspected of “thuggery.”

Special correspondent Haitham Mohamed contributed to this report.