Rescues and Arrests in Building Collapse in Bangladesh Wong Maye-E/Associated Press One of the survivors rescued Saturday from a collapsed garment factory. At least 340 people are known to have been killed. SAVAR, Bangladesh (AP) - Rescue workers pulled 29 survivors from the rubble of a collapsed building here on Saturday and vowed to continue as long as necessary to find others, despite fading hopes. At least 348 people are known to have died, crushed by blocks of concrete and mortar when the eight-story structure came down Wednesday morning. Many of the garment factories in the building were packed with employees who worked for $38 a month to produce clothing for top international brands. The police said Saturday that they had taken five people into custody in connection with the collapse, including the wife of the building owner in an effort to force him to surrender. Violent protests continued sporadically in nearby Dhaka, the capital, and spread to the southeastern city of Chittagong, where several vehicles were set on fire. Subrata Sarker, a fire official, said that many survivors were still trapped amid the debris. Mohammad Sarwar Hossain, a rescue worker, said he saw 15 people still alive. But other rescue workers admitted Saturday that the voices of survivors were getting weaker after four days of being pinned under the increasingly unstable rubble, said Brig. Gen. Ali Ahmed Khan, who runs the fire service. The building site was the scene of frenzied activity all day with soldiers, police officers and medical workers in lab coats working nonstop. Rescuers passed bottles of water and small cylinders of oxygen up a ladder leaning against the side of the building to be given to possible survivors inside. They used bare hands and shovels, passing chunks of brick and concrete down a human chain away from the collapsed structure. A local government minister, Jahangir Kabir Nanak, put the death toll at 348. A military spokesman, Shahinul Islam, said that 2,429 survivors had been accounted for, including the 29 who were pulled out Saturday. A garment manufacturers" group said the factories in the building employed 3,122 workers, but it was not clear how many were inside when it collapsed. "We will continue our operation for more survivors as long as it is required," Mr. Islam said. We are not thinking of wrapping up of our effort any time soon. The authorities shut down garment factories in Dhaka for fear of violence, which has persisted over demands that the police arrest the owners of the factories and the building. Junior Home Minister Shamsul Haque Tuku said the police had arrested two executives of New Wave Apparels, one of the five factories in the complex. The executives, Bazlus Samad, the managing director, and Mahmudur Rahman Tapash, the company chairman, turned themselves in to the police early on Saturday. Mr. Tuku said that the police had also detained the wife of Sohel Rana, the owner of the collapsed Rana Plaza building, for questioning. The authorities are still searching for Mr. Rana, who has not been seen publicly since the building collapsed. The police said they had also detained for questioning two engineers working for the municipality of Savar, Imtemam Hossain and Alam Ali. They did not say what role the engineers had played in approving the design of the building.