A huge rocket carrying a spy satellite for the United States has launched from the central California coast.

United Launch Alliance says liftoff occurred Wednesday morning from Vandenberg Air Force Base, about 150 miles northwest of Los Angeles.

The 23-story Delta IV Heavy — the largest rocket in the country — carried a satellite for the National Reconnaissance Office, which operates the nation's system of intelligence-gathering satellites.

Since the mission is classified, no other details were available.

It's the second time this type of rocket has launched from the West Coast base. The first occurred in 2011 and shook the nearby city of Lompoc. Some spectators reported hearing the rocket's roar from 50 miles away.

For the latest launch, base officials closed a nearby beach as a precaution.