TUCSON, Ariz. — An Air Force base near Tucson was on lockdown Friday afternoon amid unconfirmed reports of gunfire.

Two ambulances were sent to Davis-Monthan Air Force Base on the outskirts of town, a fire spokeswoman said. Officials at the base would not say if anyone had been shot.

Senior Airman Timothy Dunaway said traffic has been reduced to a single point entry. Cars lined up at the base’s main gate and were being turned around.

Tucson fire spokeswoman Trish Tracy says that besides the ambulances, two fire trucks were dispatched to the base.

Two elementary schools on the base are on lockdown, Dunaway said. A woman who answered the phone at Sonoran Science Academy confirmed the lockdown but would not provide further details or her name.

Davis-Monthan is adjacent to the Pima Air & Space Museum and the “boneyard” for old military and government airplanes that is a popular destination for aviation enthusiasts.

The base is the home of the 355th Fighter Wing, and provides attack airpower, combat support and medical forces, according to the base’s Facebook page.

Security at military bases has gained more attention in the last two years since an Army major went on a rampage at Fort Hood in Texas in 2009. Maj. Nidal Hasan is charged with 13 counts of premeditated murder and 32 counts of attempted premeditated murder in the shooting spree. Investigators have foiled other plots against military bases in other parts of the country since Sept. 11.

A mass shooting in Tucson in January killed six people and wounded 13, including U.S. Rep. Gabrielle Giffords.