Chinese President Xi Jinping visits a survivor from Friday's oil pipeline blast at the affiliated hospital of Qingdao University in Huangdao district, Qingdao, East China's Shandong province, on the afternoon of Nov 24, 2013. Fifty-two people were confirmed dead in the blast. [Photo/xinhuanet.com]

Chinese President Xi Jinping visited people injured in the deadly oil pipeline blast in Qingdao, East China's Shandong province, on Sunday, expressing concerns about production safety.

Xi arrived at the affiliated hospital of Qingdao University, where the injured were being treated, on Saturday afternoon, Xinhua reported.

Xi also visited families of the injured people and expressed his condolences.

The death toll from Friday's oil pipeline blast has risen to 52, with 11 others still missing, the rescue headquarters said. Rescue efforts continued Sunday despite rainy weather.

Crude oil began leaking from an underground pipeline operated by Sinopec early Friday in Huangdao district of Qingdao, according to the municipal government. The valves of the Huangdao oil warehouse were shut about 15 minutes later.

Xi listened to work reports on rescue efforts and urged more preemptive measures to prevent accidents caused by production safety violations.