Rescuers work at the core area of explosion site in Tianjin, north China, Aug. 26, 2015. The death toll from the Tianjin warehouse explosions has risen to 139 as of Wednesday afternoon, and all of them have been identified, according to the latest data from rescue authorities. [Photo/Xinhua]

BEIJING - Police have arrested 12 suspects involved in massive blasts in Tianjin which killed 139 and devastated the port area, the Ministry of Public Security said Thursday.

The 12 people include chairman of Tianjin International Ruihai Logistics Co. Ltd. Yu Xuewei, vice-chairman Dong Shexuan, and its three deputy general managers, according to the police.

Related: All residential buildings damaged in Tianjin blasts are safe, inspectors say

By TANG YUE (China Daily)

Inspectors have given 11 of the 12 apartment buildings worst hit by the explosions on Aug 12 in Tianjin Binhai New Area the highest rating for safety, according to local authorities.

The ratings were part of a post-inspection report released on Wednesday by the municipal Bureau of Land Resources and Housing Management.

Only one building received a lower rating－the No 2 building of Vanke Qingshuilanwan. It had a fire-damaged apartment on the 19th floor, and parts of its rebar were exposed, said Zhao Yi, chief engineer of the team that conducted the inspection.

The defect will not affect the structural integrity of the building, Zhao said.

The blasts at Tianjin Port have claimed 139 lives, including 84 firefighters, and left 34 missing as of Wednesday afternoon, according to the Tianjin Information Office. A total of 527 people remained hospitalized. Of those, 10 were in critical condition.

On Tuesday, five State-owned property developers in Tianjin said they had formed an alliance to purchase blast-damaged apartments from willing residents, with a view toward reselling them after renovation.

The companies are working out a detailed plan with the guidance of the government. The move will protect the interests of the owners of the apartments, according to Di Da, chairman of Tianjin Real Estate Development Co, one of the five developers.

The Tianjin Port fire station will be rebuilt in the same place at the blast site, which is still undergoing cleanup, along with a memorial park and a couple of shopping malls.

"There will be no factories in that area in the future. It will be all green," said Zhang Bingjun, chairman of Tianjin TEDA Investment Holding Co on Wednesday, according to the micro blog of Tianjin Binhai New Area.

The municipal government said on Saturday that people who have temporary difficulty in making mortgage payments due to the blasts will not be punished by banks.