Two teenage boys have been charged with felony hate crime for vandalizing a mosque in Sterling the weekend after Sept. 11 this year. The Loudoun County Sheriff's Office said they appear to have acted alone.

The youths, ages 14 and 16, were also charged Wednesday with five counts of misdemeanor destruction of property and one count of felony destruction of property, sheriff's officials said.

A tan wall of the nearly completed mosque was spray-painted with black swastikas and racial obscenities, and six vehicles in the neighborhood were sprayed with black lines.

Sheriff's officials charged the 16-year-old with a second count of felony hate crime, contending that he returned within 48 hours of the first incident and spray-painted another swastika on the back of the building.

Sheriff's officials did not release the suspects' names because they are juveniles but said both are Sterling residents. The penalty they could receive if convicted could vary because of their ages. Officials said no court date had been set.

"This appears to be two kids working on their own," said Kraig Troxell, a spokesman for the Sheriff's Office.

Mosque officials had increased security around the complex during the 9/11 anniversary because they were concerned about the possibility of such an incident. The vandalism took place Sept. 13 or 14, after security was relaxed.

"We are happy that the perpetrators were caught," said Yasir Syeed, community relations director of the All Dulles Area Muslim Society, known as the Adams Center, which runs the mosque on 46903 Sugarland Rd. "Also, we are happy these were two individuals and not a group."

Syeed also praised neighbors and other community members, many of whom offered support after the vandalism and condemned the attacks. "The incident was not indicative of the community at all," he said.

The mosque is to open in a few weeks.

On Sept. 11, 2001, vandals spray-painted violent messages on walls, carpets and doors of another space that the Adams Center used at Community Plaza in Sterling. The center's director received a call the next morning from someone threatening Muslims. Sheriff's officials are still investigating that incident.

In another case of vandalism last year, violent messages were spray-painted throughout the space used by the Adams Center in Sterling.