Media playback is unsupported on your device Media caption Watch footage of efforts by the Chinese authorities to deal with the hornet menace

Attacks by hornets in northern China have killed 41 people since July, state-run media report.

More than 1,600 people have also been injured by stings in Shaanxi province, according to China News Agency.

It says 206 people are still being treated in hospital, with 37 patients remaining in a critical condition.

Local officials have been quoted as saying that drier and warmer weather this year may have contributed to a rise in hornet numbers in the area.

Environmental activists have also blamed rapid urbanisation for worsening the problem as more rural land is swallowed up for urban development, intruding into habitats where hornets hunt and build their nests.

The cities of Angkang, Hanzhong and Shangluo have been worst affected by the spate of attacks over the past three months.

The provincial government has dispatched pest control experts to help deal with the situation.

China News Agency says local police and fire-fighters have been given equipment and protective clothes to help remove and destroy hornet nests.

Hornet attacks are a recurring problem in Shaanxi province in particular, but the authorities have released no casualty figures for previous years.

Zhao Fang, a city government official in Ankong, told the China Daily newspaper that hornet attacks had increased in recent years as the "local ecological environment improved".

Winters have been getting milder and summers hotter and more humid in Shaanxi, which may have helped caused hornet numbers there to rise.

The Chinese term for hornets is "hu feng" - those behind the deadly attacks this summer appear to be the Asian giant hornet, or Vespa mandarinia.

They can grow up to 5cm long with a 6mm sting.

The area is also home to the smaller Asian hornet, Vespa velutina nigrithorax.