A group of 150 Iranian lawyers have urged the Islamic Republic's judiciary chief to halt the execution this week of a man sentenced to death for a murder he committed when he was 15, local newspapers said on Wednesday.

Human rights groups have criticised Iran for sentencing minors to death. Iran says it only carries out the death penalty when a prisoner reaches the age of 18.

The 150 lawyers, in a letter carried by Etemad-e Melli and other newspapers, cited media reports that Bahman Salimian was due to be hanged on Thursday in the central city of Isfahan after spending 12 years in jail.

They said issuing death sentences for juvenile offenders like Salimian was against the law and that he may have had "negative thoughts caused by depression" at the time of the crime.

"We lawyers are asking you to order a stop of the implementation of such sentences as soon as possible," the letter to judiciary chief Ayatollah Mahmoud Hashemi-Sharoudi said.

Etemad-e Melli did not name any of the lawyers who signed it nor give details of the murder Salimian was convicted of.

U.S.-based Human Rights Watch has said Iran executed six people last year for crimes committed under the age of 18 and that at least 130 other juvenile offenders were on death row.

The European Union last week said Molla Gol Hassan, an Afghan citizen sentenced for a crime he was accused of committing when he was 17, was executed on Jan. 21 and the 27-nation Union strongly condemned it.

Rights groups had praised Iran when it seemed to have ended the practice in October. But a judiciary official later clarified Iran's position, saying juvenile offenders could still face execution for murder but not for other capital crimes.

Iran regularly rejects accusations of human rights abuses, saying it is following Islamic sharia and accusing Western governments of double standards.