Media playback is unsupported on your device Media caption Phone footage shows the miners trapped underground before they were rescued

Chinese miners trapped underground for 36 days filmed emotional messages on a mobile phone before being brought to the surface by rescuers.

The four miners, at times in tears, thanked the teams above ground for working to save them.

The men were trapped by a cave-in at a gypsum mine in eastern Shandong province on 25 December.

Of 29 initially trapped, 15 have been rescued and one is confirmed dead, while 13 are still missing.

The footage, released by Chinese authorities, showed miners named as Hua Mingxi, 36, Zhao Zhicheng, 50, Li Qiusheng, 39, and Guan Qinji, 58, addressing rescuers.

"Thank you all very much, I feel relieved and secure now," says one man through his tears.

"We will remember you all forever," says another.

The phone had been sent down some days earlier with video of the rescue operation, in order to give the men hope.

Media playback is unsupported on your device Media caption China's CCTV showed footage of the four men being pulled to safety

More than 400 rescue workers were involved in the operation to reach the men, who were trapped more than 200m (656ft) underground.

A borehole was drilled down to the shaft and water and liquids were passed through.

Finally on Friday, the miners were winched up one-by-one in a specially made capsule.

China's CCTV showed dramatic footage of one of the men appearing on the surface.

Local official Zhang Shuping said the search for those still missing would continue.

The mine collapse near the town of Pingyi was so violent that it registered at China's earthquake monitoring centre.

Police are reported to have taken "enforcement measures" against several bosses at Yurong company which owns the mine, while local party officials have been sacked.

Company chairman Ma Congbo was said to have drowned himself by jumping into a mine well several days after the incident.

China has a long history of industrial accidents.

Longest known survivors in mine accidents

Image copyright AP Image caption "Los 33" - the miners trapped in Copiapo, Chile