SAVAR, Bangladesh — Rescuers using floodlights worked into the night Wednesday to attempt to free dozens of people believed trapped under an eight-story building housing garment factories that collapsed near Bangladesh’s capital, killing at least 87 people.

In some places, they were able to cut holes into the jumbled mess of concrete with drilling machines or their bare hands, and pass water and flashlights to people trapped inside.

“I gave them whistles, water, torchlights, I heard them cry. We can’t leave them behind this way,” said fire official Abul Khayer. He said rescue operations would continue through the night because many survivors were still believed to be inside the collapsed building.

Less than five months after a factory fire killed 112 people, the disaster Wednesday again underscored the unsafe conditions in Bangladesh’s massive garment industry. Workers said they had hesitated to go to work because the building had developed such large cracks the previous day that it had been reported on local news channels.

Abdur Rahim, who worked on the fifth floor, said a factory manager assured them there was no problem, so they went inside.

“We started working. After about an hour or so the building collapsed suddenly,” he said. He next remembered regaining consciousness outside the building.

Home Minister Muhiuddin Khan Alamgir told reporters during a visit to the site that the building had violated construction codes and “the culprits would be punished.

Among the textile businesses in the building were Phantom Apparels Ltd., New Wave Style Ltd., New Wave Bottoms Ltd. and New Wave Brothers Ltd., which make clothing for brands including The Children’s Place and Dress Barn.