The Revolutionary People's Liberation Party-Front says it carried out a suicide bombing at the United States embassy in Ankara, Turkey, on Friday.
In a statement on Halkin Sesi (The Voice of the People) website on Saturday, the group accused the United States of being "the murderers of the world".
The site carried two pictures of the bomber identified as Alisan Sanli, one of which showed him brandishing a gun. He was previously involved in an attack on a military compound in Istanbul in 1997.
A security guard and the bomber died in the explosion at the embassy. Three other people were wounded
The Front has carried out attacks against America and NATO in the past.
The Turkish government had already accused the group of being responsible.
State broadcaster TRT said three people were detained in Istanbul and Ankara on Saturday in connection with the bombing.