Freak hail stones the size of eggs have killed 22 people and injured 200 in China's central Henan province, local media reports say.

Hail facts

The largest can weigh a little under 1 kg and fall at more than 50 metres per second Hail storms can devastate entire fields of crops in a few minutes The biggest hailstones in the world tend to fall in north-east India In Britain there were last hailstorms with tennis ball-size hail stones in Wokingham in 1959

Trees were uprooted, vehicles damaged and power supplies disrupted by winds gusting up to over 70 km/h in the central province of Henan. Most of the deaths came when buildings in the northern town of Zhengzhou collapsed, including a petrol station.

In the neighbouring village of Yilin, a cattle feed factory collapsed killing four, the Beijing Youth Daily reported.

Hospitals were overcrowded with victims suffering from injuries caused by the hailstones and by flying debris.

Failed warning

The Henan Province Meteorological Station said it had issued a severe weather warning, but it had failed to reach the public in time.

"We said there would be a thunderstorm. It's difficult to predict hail," said station manager Gu Wanlong.

Zhengzhou Mayor Yao Daixian told Xinhua news agency he had demanded stricter housing standards.

Livestock killed

According to BBC weather experts, most hailstones are smaller than 2.5 cm (1 in) in diameter.

World's worst weather

Worst hailstorm - Germany 1984 - 400 people injured Worst snow storm - US 1993 - 500 dead Worst ice storm - Canada and US 1998 - $650m damage Worst flood - China 1931 - 3.7 million dead Worst drought - China 1907 - estimated 24 million people dead

However, they can be as big as grapefruits.

Last year, livestock, houses and farmland in seven villages were destroyed by hailstones the size of footballs and weighing up to two kilograms in the northern Nigerian city of Kano.

China is still battling with the worst flooding for a decade.

Officials said more than 800 people had died and 100 million were affected by the floods, which destroyed more than eight million hectares of crops.

Southern and western provinces suffered the biggest losses and more than 1.5 million people have had to leave their homes.