An Alexandria high school student has been charged in the slayings of a pair of young adults found dead in rural Virginia last weekend.

Mohamed A. Aly, 18, was arrested Thursday morning in Alexandria and charged with two counts of first-degree murder and two counts of use of a firearm in the commission of a felony. He was taken to the Blue Ridge Regional Jail in Halifax.

Ntombo Joel Bianda, 21, of Alexandria, and Ayanna Munne Maertens Griffin, 19, of Germantown, Md., were found dead on the grassy median of a quiet road in Halifax County about 3 a.m. on Saturday, Virginia State Police said. Both had been shot in the head. Bianda’s silver 2009 Nissan Maxima was nearby.

T.C. Williams Principal Peter Balas confirmed in an email to parents that Aly is a student at the school.

“This situation was handled today according to protocol, and the safety and security of our students and staff were never at risk,” he said in the email. “As a precautionary measure, additional security will be in place at the school tomorrow.”

Authorities did not immediately provide details about how they identified Aly as a suspect or what his relationship was to the victims. Aly’s family could not be reached for comment.

Capt. David O. Cooper II, commander of the Virginia State Police Bureau of Criminal Investigation's Appomattox Field Office, said that the arrest was the result of “state police personnel . . . working around the clock pursuing multiple leads,” with the help of the FBI, the Bureau of Alcohol, Tobacco, Firearms and Explosives, and several local police departments.

Halifax is near the border of North Carolina; the bodies were found on what police described as a “fairly isolated” stretch of Route 58.

“I’m completely lost. I don’t understand why she didn’t tell me that she was going on a trip. She tells me everything,” ­Maertens Griffin’s mother told WSLS News.

Bianda’s family declined to comment.

Magda Jean-Louis contributed to this report.