Police in north China's Hebei Province said Friday that they have detained a farmer suspected of carelessly setting a forest fire that raged for one week last month.

An investigation showed that the farmer, who is only identified by his surname, Yang, was burning straw in his field on April 12 when the fire, fueled by strong winds, got out of control and spread to the forest, said a spokesman with the province's police department.

The fire, which burnt at least 7,000 mu (about 467 hectares) of forest, was put out seven days later after more than 10,000 people and four helicopters were mobilized to fight the blaze.

Fire control authorities even fired off rainmaking rockets to help in extinguishing the blaze.