A 13-YEAR-OLD girl has been sexually assaulted by a teenager and a young man in central western NSW.

Police officers were patrolling Wagga Wagga about 10.20pm on Wednesday when they spoke to a 13-year-old who told them she had been assaulted.

An investigation resulted in the arrest yesterday of a 16-year-old boy and 20-year-old man.

They have each been charged with aggravated sexual assault.

The 16-year-old was granted conditional bail and is scheduled to appear in Wagga Children's Court on January 29.

The 20-year-old was also given conditional bail and is due to appear in Wagga Local Court on January 30.