At least 22 people were killed in a oil pipeline blast in the eastern Chinese port city of Qingdao in Shandong province on Friday morning, triggering panic among residents and fears of an oil spill.
Local authorities did not provide the number of people who were injured but said that the condition of at least seven was critical.
"The accident happened around 10:30am in Huangdao District when workers were repairing the petroleum pipeline, which began leaking oil at around 3am, according to the Qingdao government's publicity office," state media reported.
The 176km pipeline, which links oil depots in Huangdao to Weifang City home to a few petrochemical plants, is owned by China's largest oil refiner Sinopec.
The explosion created a crater and debris of concrete slabs were scattered around the accident site. The impact also shattered the windows of vehicles parked on neighbouring streets. Thick, black smoke bellowed up to the sky and could be seen from miles away.
Local authorities urged residents to remain calm.
"Oil flow through the pipeline was shut down at about 3:15am. The fire has been put out, and barricades have been set up to stop the oil from entering the sea, according to a comment posted on Friday afternoon on the official microblog of the Qingdao municipal environmental protection bureau on Sina Weibo," state-run Xinhua news agency said.
Sina Weibo is China's Twitter-like microblogging site.
An oil spill was also spotted near the accident site.
"An oil belt with a length of two to three meters could be seen in waters around the explosion spot as of 2:40pm. No new oil leakage from the pipeline had been found," the report said.
While sources with the city's maritime safety administration told Xinhua that they had not received any report on blast-related pollution in the sea so far, they have strengthened patrolling around the coastal areas close to the site.
The report added that the concentration of toxic materials in the air was under the national standard.
Huangdao District is connected with the city by the Qingdao Jiaozhou Bay Bridge.
"Xinhua reporters said the exit on the bridge leading to Huangdao has been temporarily closed and only emergency vehicles are allowed to enter. Local traffic authorities have told drivers to allow rescue vehicles to pass," the report said.