The Midwestern US state of Missouri executed a black man on Tuesday who had been sentenced to death by an all-white jury, despite numerous protests claiming the penalty smacked of racism.

Missouri Governor Jay Nixon denied clemency to Andre Cole and the US Supreme Court denied a stay of execution.

Cole, 42, was accused of stabbing and killing Anthony Curtis, a friend of his ex-wife, in 1998.

He had also stabbed his ex-wife repeatedly because she took him to court over child support payments he owed to her, but she survived.

A jury of 12 white people found him guilty, after three black jurors were dismissed.

Cole, who spent 14 years on death row, was pronounced dead at 10:24 pm (0324 GMT) in Bonne Terre, Missouri, Department of Corrections spokesman Mike O'Connell said.

Up until the last minute, Cole's lawyers, along with civil rights and human rights advocates, religious leaders and activists, petitioned and made pleas for a retrial.

Cole's execution was the 12th this year in the United States, and the third in Missouri, one of the most active death penalty states after Texas.