Tornado hits northern California town as ice storm chills Midwest

At least four people were injured after a tornado struck northern California on Saturday afternoon, according to local authorities.

The twister flipped over several cars and brought down power lines in Scotts Valley, located around 55 miles (89km) south of San Francisco, police said.

The National Weather Service (NWS) said the tornado was categorised as an EF1, one of the weakest classifications, and that it lasted around five minutes.

Elsewhere in the US, an ice storm swept into the Midwestern states of Iowa and Nebraska, heavy snowfall hit upstate New York, and severe weather warnings were issued around Lake Tahoe, which straddles the states of California and Nevada.

Earlier on Saturday, a brief tornado warning was issued to residents of downtown San Francisco and San Mateo County just before 06:00 local time (14:00 GMT).

Residents were warned to take shelter as winds of up to 60mph (96km/h) ripped through the area, the NWS said.

The city last saw a tornado in 2005, though that struck without any clear radar signature, so no warning was issued in that case, NWS meteorologist Roger Glass told AP news agency.

As of Sunday, more than 40,000 customers were still without power along the California coast, with Monterey county the worst affected, according to the PowerOutage website.

San Francisco's tornado alert came just a week after the city saw its first ever tsunami warning.

The brief advisory was issued for northern California and southern Oregon following a magnitude 7.0 earthquake that hit off the northern coast of the state.

It was later rescinded, and no injuries were reported.