A survivor is carried on a stretcher into a waiting ambulance after being evacuated from a garment factory building that collapsed Wednesday in Savar, near Dhaka, Bangladesh, Saturday, April 27, 2013. Police in Bangladesh took five people into custody in connection with the collapse of a shoddily-constructed building this week, as rescue workers pulled 19 survivors out of the rubble on Saturday and vowed to continue as long as necessary to find others despite fading hopes. (AP Photo/Wong Maye-E) A survivor is evacuated from a garment factory building that collapsed Wednesday in Savar, near Dhaka, Bangladesh, Saturday, April 27, 2013. A survivor is given oxygen as she was evacuated from a garment factory building that collapsed Wednesday in Savar, near Dhaka, Bangladesh, Saturday, April 27, 2013. A survivor, seen at bottom right, is evacuated from a garment factory building that collapsed Wednesday in Savar, near Dhaka, Bangladesh, Saturday, April 27, 2013. Bangladeshi relatives of garment worker Mohammed Abdullah cry as they pass others looking for missing relatives while to collecting his body at a makeshift morgue in a schoolyard near a building that collapsed Wednesday in Savar, near Dhaka, Bangladesh, Saturday, April 27, 2013. Police in Bangladesh arrested two owners of a garment factory in a shoddily-constructed building that collapsed this week, killing hundreds of people, as protests spread to a second city Saturday with hundreds of people throwing stones and setting fire to vehicles. SAVAR, Bangladesh (AP) - Police in Bangladesh took five people into custody in connection with the collapse of a shoddily-constructed building that killed at least 348 people, as rescue workers admitted Saturday that voices of survivors are getting weaker after four days of being pinned under the increasingly unstable rubble. Still, in a boost for the rescuers, 29 survivors were pulled out Saturday, said army spokesman Shahinul Islam. Most of the victims were crushed by massive blocks of concrete and mortar falling on them when the 8-story structure came down on Wednesday morning -- a time many of the garment factories in the building were packed with workers. Among those arrested Saturday were two owners of a garment factory, who a Dhaka court ruled can be questioned by police for 12 days without charges being filed. Also detained are two government engineers and the wife of the building owner, who is on the run, in an attempt to force him to surrender. Working round-the-clock since Wednesday through heat and a thunderstorm, rescuers on Saturday finally reached the ground floor from the top of the mountainous rubble through 25 narrow holes they have drilled, said Brig. Gen. Ali Ahmed Khan, the head of the fire services. "We are still getting response from survivors though they are becoming weaker slowly," he said, adding that rescue workers were now able to see cars that were parked at the ground level. The building is very vulnerable. Any time the floors could collapse. We are performing an impossible task, but we are glad that we are able to rescue so many survivors. He said the operations will continue overnight as chances fade of people surviving for a fifth day with possibly grievous injuries and the heat. The building site was a hive of frenzied activity all day with soldiers, police and medical workers in lab coats working non-stop. They used bare hands and shovels, passing chunks of brick and concrete down a human chain away from the collapsed structure. My son says that his mother will come back some day. She must return! " he cried. The bodies were kept at a makeshift morgue at the nearby Adharchandra High School before being handed over to families. Junior local government minister Jahangir Kabir Nanak put the death toll at 348. Military spokesman Shahinul Islam said 2,429 survivors were accounted for, including 29 who were pulled out Saturday.