Three children and three adult staff members died from gunshot wounds in Nashville, Tenn., on Monday after police say a female armed with two assault-style weapons and a handgun opened fire in a school.

Officials said the female appeared to be in her teens but her identity had yet to be confirmed. They said she entered the school through a side entrance and was killed by police, bringing the death total to at least seven in the shooting.

Police did not specify the ages of the victims.

Police said they responded to a call of a shooting at the school at 10:13 a.m. local time and cleared the first floor of the school. Officers then heard shots being fired on the second floor and moved toward the gunfire, engaging with the shooter and killing her. The shooter was dead by 10:27 a.m.

The only other injury reported was an officer who was cut by glass.

Police said on a typical day, there are usually around 209 students in the school.

There were no school resource officers at the school, according to police, since it is a private school.

The Nashville Fire Department said earlier on Twitter that it responded to the Covenant School, which is listed as a Christian elementary school with a preschool department, according to its website.

“We can confirm we have multiple patients,” the department said. “[T]his is an active scene.”

Metro Nashville Police Department confirmed that an “active shooter” event took place at the school and that the shooter was engaged by officers and was killed.

WKRN in Nashville reported that FBI and ATF agents were responding to the incident.

Officials said that a reunification area had been established at a nearby church.