A shooting at a US military base in San Antonio, Texas has left at least two people dead, police say.

The attack on Friday at the Joint Base San Antonio-Lackland appears to be a murder-suicide, according to Bexar County Sheriff's Office spokesman James Keith.

Joint Base San Antonio-Lackland is the home of US Air Force basic training.

The base's public affairs unit said only that there was an announcement for people on the base to close doors and turn off lights.

In 2009, Fort Hood, which is about 160 miles (257 km) from Lackland Air Force Base, was the site of the deadliest shooting at a US military base, when 13 people were killed and 31 were injured.

Every year, more than 30,000 people are shot and killed in the United States. The US averages 87 gun deaths each day as a function of gun violence, with an average of 183 injured, according to the University of Chicago Crime Lab and the Centers for Disease Control.

US shootings since 1963 have killed more Americans than all wars ever, according to a gun control advocacy group.

According to the Virginia Center for Public Safety, since former President John F. Kennedy’s assassination in 1963, more Americans have been killed as a result of gun violence than all US wars, theHuffington Post reported in January.

The horrifying figure which was first released in fliers handed out at a January 18 rally in Richmond was confirmed after it was fact-checked by PolitiFact.