The teenager, identified as Nabra Hussein, was walking with friends when they got into a dispute with a driver in Herndon, police said.

The man left the car and assaulted the girl, they said. She then disappeared.

A 22-year-old suspect has been arrested and charged with murder.

The reason for the attack was still unknown, but police said it "appears to be the result of a road rage incident".

"Our investigation at this point in no way indicates the victim was targeted because of her race or religion", the Fairfax County Police Department said in a statement.

The Washington Post reported that a group of four or five teenagers including Nabra had visited a fast-food restaurant to have a late-night meal - Muslims are currently observing the holy month of Ramadan, when they fast from dawn to sunset.

At about 04:00 (08:00 GMT), the group was confronted by the driver as they walked and rode bicycles along the street.

The All Dulles Area Muslim Society (Adams), a local community centre, said that its members came across the teenagers and directed them to their building. But one of them, Nabra, was left behind and was later reported as missing to the authorities.

During the search, which included a helicopter, police said they stopped a car driving suspiciously in the area, and took the driver, identified as Darwin Martinez Torres, into custody.

Later, at about 15:00, police found the remains in a pond some three miles (five kilometres) from the scene of the incident, police said in a statement.

A baseball bat was also found, local media reported.

An autopsy will be carried out to confirm the identity of the body and the exact cause and manner of death.

A statement by the Adams centre said: "We are devastated and heartbroken as our community undergoes and processes this traumatic event. It is a time for us to come together to pray and care for our youth."

Nabra's mother, Sawsan Gazzar, told the Washington Post: "I think it had to do with the way she was dressed and the fact that she's Muslim."

Meanwhile, an online campaign to help the girl's family has already raised $189,000 (£150,000).