Chinese police have arrested 12 people over giant explosions that killed at least 145 people and devastated a swathe of a Chinese port city, state media said Thursday as prosecutors probe 11 officials for neglecting their duties.

The official Xinhua news agency said the dozen formally held include the chairman and senior managers of the firm whose chemical storage facility exploded in the northern city of Tianjin two weeks ago, in the country's highest-profile industrial accident in years.

The death toll from huge explosions in the northern Chinese port city of Tianjin nearly two weeks ago has risen to 135, officials said Tuesday.

A total of 38 people were missing and 582 were still in hospital, a total of 36 of them in critical or serious condition, local officials announced on Sina Weibo, a Chinese version of Twitter.

China's powerful State Council, or cabinet, has vowed to conduct a "rigorous" investigation into the cause of last week's explosions in the northern port city of Tianjin as the death toll rose to 121, state media reported on Saturday.

The government will publish the findings of the investigation, which it pledged would be timely and accurate, the official Xinhua news agency reported.

Four new fires broke out Friday in the devastation left by giant explosions in the Chinese port city of Tianjin last week, state media reported, as clean-up efforts continued.

New fires have repeatedly broken out on the site, which is scattered with smoldering chemicals and flammable substances, the official Xinhua news agency said. Pictures of the area have regularly shown smoke rising from various points.

More transparency from Chinese authorities on the handling and storage of hazardous waste could have mitigated, or possibly even prevented, the disaster in Tianjin, a U.N. expert said Wednesday. 

Around 700 tons of highly toxic sodium cyanide were at the site devastated by major blasts last week, which killed at least 114 people, with fears rising that spreading pollution could cause further suffering. 

Hundreds of tons of highly poisonous cyanide were being stored at the warehouse devastated by two giant explosions in the Chinese port city of Tianjin which killed 112, a senior military officer said Sunday.

The comments by Shi Luze, chief of the general staff of the Beijing military region, were the first official confirmation of the presence of the chemical at the hazardous goods storage facility at the center of the massive blasts.

Thousands of burned-out cars lie in neat rows alongside mountains of crushed shipping containers, the smoldering frontline to enormous explosions that paralyzed one of China's most important ports and industrial zones.

The Binhai New Area in northern China, where the blasts killed scores of people and injured more than 500, is a giant logistics hub more than twice the size of Hong Kong.

Huge explosions at a container port in the northeastern Chinese city of Tianjin have injured at least 300 people, state media outlets and officials said Thursday.

The state-run Beijing News said on its website that between 300 and 400 people had been admitted to hospitals in the city, east of Beijing. It said the explosions shattered windows and knocked off doors of buildings in the area.

Chinese police have named two suspects from the restive far-western province of Xinjiang after five people were killed in car crash on Beijing's Tiananmen Square, reports and documents said Tuesday.

The incident -- in which an SUV vehicle drove along the pavement, crashed into crowds and caught fire at the capital's best-known and most sensitive site -- killed three people in the car and two tourists, according to Beijing police.

Scores of people were injured when police in southern China broke up clashes between migrant workers and the local population in the latest unrest to hit the nation, a rights group said Tuesday.

Police stepped in to break up fighting between the workers largely from Sichuan province and the locals in Shaxi township in Guangdong province Monday night, the Information Centre For Human Rights and Democracy said.