ABRAKA, Nigeria (AP) — A human rights lawyer says three convicted criminals have been secretly executed in the first hangings in Nigeria since 2003. The executions breach a seven-year moratorium on the death penalty here.

Chino Obiagwu of the Legal Defense and Assistance Project says three men who had been death row inmates for 20 years were hanged in Benin Prison in southern Edo state on Dec. 23. All had been convicted of armed robbery.

Obiagwu tells The Associated Press that his organization wrote to the Edo state governor on Dec. 21 warning that the men had outstanding appeals, making the hangings "an unlawful act."

Edo state executed four convicted criminals in 2013, breaching Nigeria's 2009 moratorium on the death sentence.

Officials in Edo did not respond to requests for comment.