Satellite images have revealed the scale of two wildfires spreading in southern California.

The Sandy Fire ignited on Monday morning in the city of Simi Valley, north-west of Los Angeles, according to California Governor Gavin Newsom.

Satellite images taken just after noon local time (20:00 BST) on Monday show a large plume of smoke rising into the air just south of the city.

California fire officials said on Tuesday morning that 750 firefighters were being supported by 'night-flying water dropping helicopters' to target hotspots.

The Simi Valley Police Department stated that an individual hit a rock with a tractor, which sparked the fire.

The fire has spread across 1,364 acres (550 hectares) and no part of it has been contained, officials report.

Data from NASA's wildfire monitoring platform shows active hotspots moving south overnight.

More than 10,000 homes have been evacuated from Simi Valley and surrounding communities, with a further 3,500 homes under evacuation warnings.

Los Angeles mayor Karen Bass noted there are currently no expectations for the blaze to spread to the city, but cautions have been advised.

The wind conditions have played a crucial role in the fire's spread; high winds were forecasted earlier, but they eased later in the day.

Simi Valley Unified School District officials announced campus closures on Tuesday.

This year has already seen catastrophic fire incidents in California, stressing the critical need for preparedness and response.

Another fire on Santa Rosa Island has burned 14,600 acres, affecting the Channel Islands National Park.

With firefighting resources stretched thin, the community faces an ongoing threat as conditions remain volatile, underscoring the persistent dangers of wildfires in the region.