CAIRO — Egyptian authorities said Thursday that they arrested dozens of Muslim Brotherhood members across the country and seized their land, stocks, and vehicles, a muscular response one day after the military-backed government declared the Islamic group a terrorist organization.
Social and charitable groups even loosely associated with the group struggled after their funds were frozen by the state. It was a new level of disruption to a society already riven by violence and suspicion in the months since the military ousted Mohammed Morsi, Egypt’s first democratically elected president and a Brotherhood leader.
Egypt’s new leaders clearly signaled that they had opened a wide-ranging and possibly protracted war on every facet of the Brotherhood’s activities, with the terrorism designation giving the security forces greater latitude to stamp out a group deeply rooted in Egyptian social and civic life.
The government had also sought to deny the group foreign help or shelter, urging other Arab governments to honor an antiterrorism agreement and shun the organization.
But there were indications that the government might have overreached. After widespread confusion and concern about the funds cutoff, in particular, government officials partly reversed course Thursday night, saying that the organizations whose funds had been frozen — more than a thousand of them — would be allowed access to money to continue operating.
One of the operations caught in the whipsaw was the Islamic Medical Association, a network of hospitals founded by a Brotherhood leader in the 1970s that now serves more than 2 million patients a year, mostly in poor neighborhoods.
At two of the network’s hospitals in Cairo, most of the local residents waiting for treatment Thursday said they did not belong to the Brotherhood and did not regard the facilities as part of the movement’s operations.
Instead, they saw clean, efficient, and affordable alternatives to the government’s poorly managed hospitals.
A doctor at one of the facilities, Central Hospital in the Nasr City district of Cairo, said Thursday that admissions had already dropped by nearly half.
Many apparently were scared away by news that funding had been cut and worried that even going to the hospital would be seen by the security forces as supporting the Brotherhood.
Police arrested 16 Brotherhood members in the Nile Delta province of Sharqiya on charges of belonging to a terrorist group, the state news agency MENA said.
Another 54 were arrested on accusations they attacked police stations or incited violence.
Private TV networks also aired the number for a hot-line for people to report ‘‘members of the terrorist Brotherhood’’ to the government — raising the possibility of citizens turning on citizens and increasing the group’s isolation.