Beijing, Shawwal 28, 1436, August 13, 2015, SPA -- A massive, deadly explosion rocked Tianjin, a major port city in north-eastern China, Chinese state-run news agency Xinhua reported early Thursday, according to dpa. At least seven people were killed and more than 300 injured, the People's Daily reported online. Xinhua reported that two firefighters were missing and four injured from among 12 crews sent to a reported warehouse fire late Wednesday. The blast occurred about 40 later, around 11:30 pm (1530 GMT). Nine more fire crews were sent as reinforcements after the explosion. Residents fleeing their homes "feared an earthquake," the agency said. The cause of the blast was not immediately known, Xinhua said. Video of a massive explosion against the backdrop of a city skyline flooded social media, and photos online showed injured people fleeing the scene. The blast was felt kilometres away, with reports of broken windows and fishtanks. An official at a nearby hospital said that more than 50 people were there for treatment of injuries with more expected to arrive, Xinhua reported. Most of the injured suffered wounds from broken glass or flying debris. --SPA 03:08 LOCAL TIME 00:08 GMT www.spa.gov.sa/w