BEIRUT — Rescue workers suspended a search for potential survivors late Thursday night at a building that collapsed in the Aug. 4 Beirut port explosion amid fears that a wall would collapse on the team, stirring fury among residents and onlookers hoping for what might be a small miracle.

Reports that signs of life had been detected, 30 days after the devastating explosion, amid the ruins of the once vibrant Gemmayzeh neighborhood raised hopes across Beirut that some good news might emerge from the wreckage of the city.

Instead, the decision to call off the search until Friday morning revived the sense of anger and frustration among weary, traumatized Beirutis.

As the rescue workers began to depart, onlookers and local residents angrily denounced the decision to pull out, including Lebanon’s renowned, Oscar-nominated director Nadine Labaki. “There could be someone alive,” she said. “That cannot wait until tomorrow morning.”

“You have no brains,” shouted another woman. “If your sister or mother was there, would you leave them?”

Some onlookers donned hard hats and clambered onto the building to try to continue the rescue effort themselves, but they were escorted down by soldiers.

Under the weight of popular pressure, the search was resumed shortly after 1 a.m. Friday.

The rescue effort was launched after a sniffer dog working with Topos, a Chilean rescue team, responded to a smell outside the pile of rubble that was once an elegant, four story pink Ottoman house hosting a tequila bar on the ground floor, according to humanitarian workers involved in the rescue effort.

Specialist equipment deployed by the team subsequently detected the presence of two bodies, one apparently an adult and a smaller one, curled up, that may belong to a child, said Edward Bitar of Live Love Lebanon, a humanitarian organization that is part of the rescue effort. In one of them, the equipment detected a pulse indicating a heartbeat of 18 beats per minute, he said.

Several hours later, that had fallen to 10 beats a minute, he said.

“We’re not sure if they are alive. One of them is for sure dead,” Bitar said. “We are not even sure there are bodies inside. That is what the equipment is showing. Sometimes the equipment shows something and there is nothing inside."

“We don’t want to raise false expectations,” he added. “But if there is a one percent possibility of finding anyone…we are doing everything we can.”

The director of operations at Lebanon’s Civil Defense agency seemed skeptical that there were any survivors after such a long time. He said the safety of the rescue teams was paramount.

“We cannot lose ten persons for one person,” he said. “Especially as in this case we don’t have any idea whether there is a person or not.”

The incident is likely to raise questions about whether the Lebanese authorities, who were slow to respond to the disaster from the outset, have been as vigilant as they might have been in the search-and-rescue operation.

Bitar said a French team reported that their sniffer dog had detected a smell at the scene last week, but no one followed through. Some members of the angry crowd said they had been begging the authorities to send rescuers because they believed there could be people trapped inside.

“We told you two weeks ago there is a soul there, but we heard nothing from you,” another member of the crowd shouted.

One of the rescue workers, who asked not to be named, said the Chilean team, whose dog, Flash, had first alerted them to the possibility of survivors, opposed the decision to call off the search, but that could not be independently confirmed.

The Topos team is known worldwide for its rescue work, notably during the Haitian earthquake when they rescued a person who had been buried for 27 days, the local Daily Star newspaper reported.

The news that there may still be survivors gripped the city on the eve of somber commemorations planned to mark one month since the blast on Friday. Nearly 200 people died, over 6,000 were wounded and vast swathes of the city were destroyed when about 2,700 tons of ammonium nitrate blew up at Beirut’s port.

Taylor reported from Washington.