The use of substandard subway cables in Xi'an, capital of Shaanxi province, has led to the punishment of 122 officials for their responsibility in the case, the central government said on Thursday.

Sixteen of the officials are of the prefecture-city level, which is directly beneath the ministerial level.

All of the officials are receiving disciplinary or criminal punishment according to laws and regulations, according to a statement from the State Council, China's Cabinet.

In addition, eight people from the cable manufacturer, Shaanxi Aokai Cable Co, have been arrested, and 19 people - all employees of the Shaanxi branches of related State-owned companies - have been placed under investigation, the statement said.

An online post on March 16 claimed that Subway Line 3 in Xi'an, which opened on Nov 8 and handles on average over 340,000 trips a day, used substandard cables that might ignite and release toxic gases.

An investigation by the metro company and local government confirmed that substandard cables were used, but they hadn't affected subway safety or operations, and it was decided to replace all the substandard cables.

"A central government investigation group has concluded that it's a serious case in which enterprises illegally produced and sold substandard products," the State Council statement said.

Employees of subway construction agencies colluded with employees of the manufacturer to use counterfeit products, while local authorities' negligence in supervision was also at fault, the statement said.

Shaanxi's provincial government has been ordered to submit a profound written self-criticism to the central government and to revoke all of Aokai's authentication certificates, trademarks and licenses.

A full check of all related projects has been ordered, as well as replacement of all problematic cables as soon as possible. A nationwide inspection of cable production is to be launched. The State Council also asked for a better bidding process in government procurement and an upgraded purchasing system.

"Corruption must be resolutely prevented and punished, and there should be zero tolerance toward illegal behaviors that might endanger people's lives and property," it said.

China Railway Corp said on March 25 that it had replaced all cables provided by Aokai. Affected railway lines include those connecting Baoji to Lanzhou, Xi'an to Chengdu, Chongqing to Guiyang, and Lanzhou to Chongqing. Metro systems in Chengdu and Hefei were also found to have used cables from Aokai.