Workers said poor-quality materials were used during construction by a Chinese developer as it sought to cut costs. Investigators also said they found substandard steel bars in the rubble.

Officers questioned four Chinese men who were found removing 32 files from containers behind the collapsed building, a police official said.

A 7.7 magnitude earthquake recorded on Friday near the Burmese city of Mandalay has killed at least 3,145 people, with at least 4,589 injured and hundreds more missing and feared trapped under rubble.

Myanmar's ostracised leader Min Aung Hlaing will leave his disaster-stricken country for a rare trip to a regional summit, as aid groups called for restrictions to be eased to reach quake survivors.

Myanmar junta chief Min Aung Hlaing has also rejected calls for a ceasefire to facilitate the delivery of desperately needed relief supplies.

For most of the day, the mood was somber among relatives of dozens of workers missing at the site where a multi-story building collapsed in Bangkok. A volunteer group with sniffer dogs took time away from its grim task of searching the rubble to bring the animals on a visit top help lift their spirit.

The UK's Disasters Emergency Committee (DEC) is launching an appeal to help the thousands of people injured and displaced as a result of last week's powerful earthquake which struck Myanmar and the wider region.

The death toll from the massive earthquake that hit Myanmar nearly a week ago rose Thursday to 3,085 as more bodies were found by search and rescue teams, the military-led government said. In a short statement,

Chinese teams have been some of the main visible signs of official assistance in affected areas like Mandalay and Sagaing, where residents said they received no help from the military.