"These men had the purest of hearts. A shining example to China, may their brave souls now rest in peace."

This is just one of the thousands of comments on Chinese social media hailing the firefighters caught up in the huge explosions in Tianjin.

But amid the praise there has been criticism of how the incident was handled

Many firefighters were already at the scene before the explosions took place, trying to douse a warehouse blaze. They were then caught up in blasts so large they could be seen in space.

At least 21 firefighters have been confirmed dead, with about 70 firefighters reported as missing. More than 1,000 had been sent to tackle the flames.

On Friday, a 19-year-old firefighter, named as Zhou Ti was pulled alive from the debris.

The efforts of the Tianjin firefighters have featured prominently on Chinese media, old and new. "If we don't rush to the scene, who will?" the Guangzhou Daily highlighted one as saying.

An exchange on messaging service WeChat, purportedly between a fireman heading to the blast site and a friend, has been widely shared.

In it, the fireman tells his friend: "If I don't come back, my father is your father." He survived, according to Chinese state media.

Those that did not have begun to be identified - they include a 25-year-old newlywed, who leaves behind a pregnant wife, according to the Shanghaiist.com. The youngest was just 18.

In it, the fireman tells his friend: "If I don't come back, my father is your father." He survived, according to Chinese state media.

Those that did not have begun to be identified - they include a 25-year-old newlywed, who leaves behind a pregnant wife, according to the Shanghaiist.com. The youngest was just 18.