In its first session since a devastating explosion rocked Beirut last week, Lebanon’s Parliament approved a state of emergency that extends sweeping powers to the army in the city, a situation that rights groups have said could pose a threat to freedoms.

A two-week emergency was first declared by the cabinet in an emergency session with President Michel Aoun the day of the explosion, but the Parliament’s approval makes the measure official and has raised concerns about enabling a crackdown on protesters and those critical of the government.

The state of emergency allows the army to impose curfews, ban assemblies and impose censorship on media organizations and publications if it deems them threatening to national security, and also extends the ability of officials to try civilians in military courts. It will last until Aug. 21, but can be renewed.

The decision to confirm the state of emergency came as widespread protests continue over the mishandling of the country’s affairs that many believe led to the explosion, which was triggered by a fire that ignited some 2,750 tons of ammonium nitrate stored in Beirut’s port since 2014. Officials had known for years that highly explosive materials were being kept at the site, which is the country’s main port.

Turmoil has gripped the government as well. Lebanon’s cabinet resigned on Monday as fury over the explosion grew. But ministers will stay on in a caretaker capacity until the country’s president appoints a new government.

Many believed that the resignation of the cabinet leaves the country back at an impasse it faced last fall when earlier protests forced the resignation of Prime Minister Saad Hariri. Little has changed for the country’s most powerful politicians since then, a situation that protesters say has led to continued widespread corruption and mismanagement.

Karim Makdisi, an associate professor of international politics at the American University of Beirut, called the approval of the emergency measures a “very dangerous development that may lead to abuse of army power without recourse for citizens,” in a post on Twitter.

The decision was passed during a parliamentary session convened in the theater of Beirut’s UNESCO Palace, because the Parliament’s own chambers were severely damaged in the blast.

The government had already implemented a “state of general mobilization” in March to allow it to impose restrictions related to the coronavirus pandemic, including curfews, and some legal groups have questioned why an additional state of emergency was imposed.

Karim Nammour, a lawyer and board member of The Legal Agenda, a group that monitors public policy in Lebanon, said the declaration of a state of emergency followed a “repressive approach” similar to that used to respond to previous emergencies.

“The law doesn’t really specify what constitutes a threat to security, so this can be wildly interpreted in order to include other activities that are not necessarily threatening to security but are rather not compatible to the regime or powers’ view on how things should go,” he said.

He said that letting military authorities forbid any publication of content that it considers a threat to security was the most alarming aspect of the emergency measure because of the role the press plays in holding the authorities to account.

Recovery efforts are still in their early stages in the city, where the explosion caused an estimated $10 billion to $15 billion in damage, according to the governor of Beirut. International groups and nongovernmental organizations have taken the lead in the aid efforts.

On Thursday, David Hale, a senior U.S. diplomat, visited Beirut. While touring a neighborhood damaged in the explosion, Mr. Hale said the F.B.I. would take part in the investigation into the cause of the blast at the invitation of local officials, according to the national news agency of Lebanon.