At least 21 people are reported to have died after tornadoes tore through parts of two US states.

Officials in Kentucky said there had been 14 deaths due to severe weather while seven people were killed in Missouri, including five in the city of St Louis.

The Kentucky tornado struck in Laurel County, in the south-east of the state, in the early hours of Saturday. Officials said they expected the death toll to rise.

Missouri officials said 5,000 buildings were damaged, roofs destroyed and power lines knocked downed as a tornado struck on Friday.

About 100,000 properties in St Louis were left without power and the fire department said house-by-house searches were conducted in the worst-affected areas.

Authorities in Kentucky said there were also severe injuries reported. "The search is continuing in the damaged area for survivors," said Laurel County Sheriff John Root in a post on social media.

National Weather Service radar suggested the tornado touched down shortly after 14:30 local time in the west of the city close to Forest Park - home to St Louis Zoo and the site of the 1904 Olympic Games.

St Louis Fire Department said three people had to be rescued after part of the nearby Centennial Christian Church collapsed. One of those people died.

A curfew was imposed from 21:00 to 06:00 local time in the two areas where most of the damage took place, to prevent injuries from debris and reduce the potential for looting.

St Louis Mayor Cara Spencer said: "The loss of life and the destruction is truly, truly horrendous.

"We're going to have a lot of work to do in the coming days. There is no doubt there, but tonight we are focused on saving lives and keeping people safe and allowing our community to grieve."

The US National Weather Service said tornadoes also hit neighbouring Illinois, with more severe weather conditions stretching eastwards to the Atlantic coast.