Egyptian President Abdel Fattah Al-Sisi has signed off on an anti-terrorism law that gives authorities more sweeping powers to ban groups on charges ranging from harming national unity to disrupting public order.

The move, announced in the official Gazette, is likely to increase concern among human rights groups that the government has rolled back on freedoms gained after the 2011 uprising that ended a three-decade autocracy under Hosni Mubarak.

Authorities have cracked down hard on the Islamist, secular and liberal opposition alike since then army chief Sisi toppled elected Islamist president Mohamed Mursi in 2013 after mass protests against his rule.

According to the government's Gazette, the law enables authorities to act against any individual or group deemed a threat to national security, including people who disrupt public transportation, an apparent reference to protests.

Loose definitions involving threats to national unity may give the police, widely accused of abuses, a green light to crush dissent, human rights groups say.

The Interior Ministry says it investigates all allegations of wrongdoing and is committed to Egypt's democratic transition.

Under the mechanism of the law, public prosecutors ask a criminal court to list suspects as terrorists and start a trial.

Any group designated as terrorist would be dissolved, the law stipulates. It also allows for the freezing of assets belonging to the group, its members and financiers.

Since taking office in 2014, Sisi has identified Mursi's Muslim Brotherhood as a threat to national security.

He has linked the Brotherhood, the region's oldest Islamist grouping, with far more radical groups, including one based in Sinai that supports Islamic State, allegations it denies.

Hundreds of supporters of the Brotherhood, which says it is a peaceful movement, have been killed and thousands arrested in one of the toughest security crackdowns in Egypt's history.

Since Mursi's fall, Sinai-based militants have killed hundreds of police and soldiers, and the beheading of up to 21 Egyptians in neighbouring Libya prompted Sisi to order airstrikes against militant targets there.

Some Egyptians have overlooked widespread allegations of human rights abuses and backed Sisi for delivering a degree of stability following years of political turmoil triggered by the 2011 Arab Spring uprising.  - Reuters