Pope Francis took the opportunity to express his solidarity for all victims of the recent explosions at a port in northern China.

Addressing the crowds in St Peter's Square, the Pope said the victims were very much in his thoughts.

"Dear brothers and sisters, my thoughts go at this time, to the population of the city of Tianjin in northern China, where some explosions in the industrial area have caused many deaths, injuries and extensive damage," said Pope Francis.

"I assure my prayers for those who died and for all those who are suffering from this disaster; the Lord will give relief to them and support to those engaged in alleviating their suffering," the pontiff added.

The two massive explosions at the Chinese port of Tianjin ripped through parts of the terminal on Wednesday night killing 85 people and wounding more than 700, officials and state media said.

Meanwhile, new explosions and fires have rocked Tianjin as one survivor was pulled out and authorities ordered evacuations to clean up chemical contamination.

Angry relatives of firefighters missing in the disaster stormed a government news conference to demand information on their loved ones.