Three members of a school chorus accused of singing a Kurdish rebel song during a U.S. tour have been acquitted by a Turkish court, their lawyer said Thursday.

Lawyer Baran Pamuk says the court ruled that his clients, aged 15-18, didn't intend to put out propaganda on behalf of the separatist Kurdistan Workers' Party.

Pamuk says he believes a juvenile court trying six younger members of the chorus is likely to drop the charges. He said that prosecutors have launched an investigation into the director of the children's chorus.

The children were charged after returning from a tour of the United States in October for singing a song called "Ey Raqip" or "Hey Enemy" at a music festival in San Francisco. The song is regarded as a rebel song.

They could have faced five years in prison if they had been convicted.

The nine were members of a 15-person choir from the municipality of Diyarbakir, the largest city in the predominantly Kurdish southeast.

Pamuk told the court the children did not even understand the words of the song, which was composed in the 1940s.

The rebel group has been fighting for self-rule in mainly Kurdish areas of southeastern Turkey since 1984. The violence has killed tens of thousands of people.

The United States and the European Union considers the PKK a terrorist organization.