SAN FRANCISCO, June 19 -- The fast-growing Sites wildfire in Northern California remained just 5 percent contained on Wednesday afternoon, officials said.

The Sites Fire, about 100 miles northwest of Sacramento, capital city of the western U.S. state of California, broke out Monday, and is among over a dozen wildfires that have ripped through the state.

The blaze, currently the largest and fastest growing wildfire in Northern California, has engulfed some 15,656 acres in Colusa County. Evacuations are ongoing, according to the California Department of Forestry and Fire Protection.

In Sonoma County, the Point Fire, which erupted Sunday in Geyserville and has burned more than 1,207 acres, was 50 percent contained as of Tuesday evening.

In Calaveras County, a blaze that erupted Monday afternoon has been dubbed the Aero Fire, and it has been deemed a threat to more than 3,600 structures. It was 33 percent contained on Wednesday afternoon, having charred more than 5,351 acres.

Officials warned that the risk of new fires erupting in Northern California remained high.

The probability of ignition is "still up at around 100 percent," said fire behavior analyst Jonathan Pangborn of the California Department of Forestry and Fire Protection.

  - Xinhua