August 18, 2015: Paramilitary police mourn for firefighters and soldiers killed during the explosions in Tianjin. With a swathe of one of the world's busiest ports in ruins, more than a billion dollars in losses, and some major multinational firms still unable to access their premises, the economic impact of the Tianjin explosions could reverberate for months.

Chinese police have arrested 12 people suspected of involvement in this month's massive explosions in the city of Tianjin that killed 139 people and devastated the port area, the state-run Xinhua news agency said on Thursday.

Among those arrested were the chairman, vice-chairman and three deputy general managers of Tianjin Dongjiang Port Ruihai International Logistics, the company that had been storing the chemicals that blew up, the agency said, quoting police. It did not say who the rest were.