MABLETON -- A Cobb County high school ROTC instructor has been charged with five felony counts in connection with the alleged of sexual assault of one of his female students, authorities said.

The arrest warrant accuses Charles Nelson, 44, of Powder Springs of having physical contact with the Pebblebrook High School student between August 2002 and 2004 at the school's campus in Mableton.

In addition to the felony charges, the instructor also faces misdemeanor charges of sexual battery and simple battery, authorities said.

The man was taken into custody Tuesday and held at the Cobb County jail before being released after he posted a $10,000 bond, a sheriff's department spokeswoman said.

Cpl. Dana Pierce, a Cobb police spokesman, said he was unsure why it took so long for the allegations against Nelson to surface.

School district spokesman Jay Dillon said Nelson has been placed on paid administrative leave until the issue is resolved. The girl reported the alleged assault in early November.

wsbtv.com Staff Writer Alfred Charles contributed to this report.