ISLAMABAD, July 5 (Xinhua) -- The death toll from the collapse of a residential building in Pakistan's southern port city of Karachi rose to 17 as more bodies were recovered from the debris, a spokesperson of the state-owned rescue organization Rescue 1122 told Xinhua on Saturday morning.

"The life detection equipment indicates that at least 10 people are still alive under the rubble. We're working urgently but carefully to rescue them," Hassaan Ul Haseeb Khan, the operation's spokesperson, told Xinhua from the site.

Rescue teams, equipped with five disaster response vehicles, two snorkels, several ambulances, cranes, and lifters, reached the site shortly after receiving distress calls, and over 100 personnel are actively participating in the operation to locate and retrieve victims from the debris, he added.

He said the operation, which has continued for over 20 hours, may require another seven to eight hours to complete.

Talking to Xinhua, Mayor of Karachi Murtaza Wahab said that they had previously declared the building "dangerous," directing the residents to evacuate it.

The five-storey structure, located in the densely populated Lyari area, collapsed on Friday, causing scenes of panic and distress.

Authorities have launched an investigation into the collapse and are surveying other nearby buildings for safety concerns. ■