Chad said Tuesday it had suspended all operations of the local unit of China National Petroleum Corporation for flagrant violations of environmental regulations while exploring for crude.

Oil Minister Djerassem Le Bemadjiel told AFP the decision was taken after officials had visited Koudalwa some 200 kilometers (125 miles) south of the capital N'Djamena, where the local unit of the state-owned Chinese company was exploring for oil.

"Not only did they not have equipment to clean up oil that spilled out, but they intentionally let it spill in order to cut costs," said the minister.

Le Bemadjiel said CNPC's local unit had dug huge trenches and let oil flow into them, and then had it removed by local workers without protective gear.

He criticised the "flagrant violations" and "unacceptable behaviour" by the company.

Le Bemadjiel said the managers of the company would be held responsible for the violations, but did not say how long its operations would be suspended.

CNPC's local unit has explored for oil in Chad since 2009 and also operates a refinery in the central African country.

Chad, which began producing oil in 2003, had an output of 120,000 barrels per day in 2011 according to official sources.