Texas prison officials on Wednesday executed convicted killer Martin Robles for the shooting deaths of two young men nearly nine years ago, who belonged to a rival street gang in Corpus Christi.

Martin Robles, 33, was given a lethal injection of drugs and pronounced dead at 6:21 p.m. local time, a Texas Department of Criminal Justice spokesman said.

He had exhausted his appeals, and no late court actions to try to spare him were made as his lethal injection neared.

Prison officials said that Robles requested no visitors and no relatives or friends were present to witness his execution. His final statement before he was executed was "I love Israel". He died nine minutes after the drugs entered his blood.

Robles was convicted in the November 2002 slayings of two 19-year-olds, Jesus "Chuy" Gonzalez and John Commisky.  Robles belonged to a gang called the Raza Unida, or "RU," that was squabbling over drug-dealing turf and feuding violently with another gang that counted the victims as members, according to the Houston Chronicle.

On Nov. 12, 2002, Robles and another man entered the Corpus Christi home, where Gonzalez and Commisky were asleep. The Texas Attorney General's report said that Gonzalez was shot at least 15 times, mostly in the head, while Commisky was shot 14 times, mostly in the back. Both victims were killed as they slept.

A witness in the house recognized Robles, when he removed his mask as he got into a car to drive away, the report said.

Robles' accomplice, Joe David Padron, was tried separately and sentenced to life in prison.

Two inmates testified that Robles said he had killed the men, including one inmate who said Robles told him Padron had not pulled the trigger, reports Reuters.

Robles had a lengthy juvenile record at the time of the shooting. He was convicted of murder when he was 17 and sentenced to six years in prison. He had been out of prison about a year after serving the full sentence, when he was arrested for the November 2002 shooting.

Robles will be the ninth person to be executed in Texas this year. Texas reportedly has executed more inmates than any other state, since the death penalty was reinstated in the U.S. in 1976 in the Gregg vs Georgia decision. The Texas Department of Criminal Justice statistics indicate that 472 executions have been carried out in the state since 1976, with the first execution since the reinstatement carried out in 1982. Roble's execution puts the figure at 473. Earlier, Mark Stroman was executed on July 20.

Five more executions are scheduled in Texas for September.

Capital punishment has been a widely-debated subject around the world. Human rights groups like Amnesty International have been strongly opposed to the death penalty, which they believe is "the ultimate denial of human rights. It is the premeditated and cold-blooded killing of a human being by the state. This cruel, inhuman and degrading punishment is done in the name of justice. It violates the right to life as proclaimed in the Universal Declaration of Human Rights," reads a posting on the organization's website.

As of 2010, 96 countries had abolished death penalty for all crimes and more than two thirds of the countries in the world had abolished the death penalty in law or practice, says Amnesty.

In the U.S., still 34 states, besides the federal government the U.S. Military, have capital punishment.