The execution of Georgia man Troy Davis in connection with the murder of an off-duty Savannah police officer 22 years ago has evoked protests in different parts of the world.

The European Union expressed its disappointment over the execution and repeated its request for a universal suspension on capital punishment.

The social networking sites were abuzz with cries of protests and agitated criticisms against the justice system.

We strongly deplore that the numerous appeals for clemency were not heeded, CNN quoted a statement from the French foreign ministry.

Davis was convicted in the 1989 murder of police officer Mark MacPhail of Savannah. MacPhail, 27, was operating as a security officer outside a Savannah bus station on Aug. 19, when he was gunned down. MacPhail left behind his wife and two young children.

Davis was 19 years old when he was arrested for the murder. His supporters believed that racism played a major role in Davis's execution since he was black and the slain cop was white.

Anything that can be racialized, I think, deeply affects Columbia's students, as the critical people that we are, Felicia Bishop, BSO president, told Columbia Daily Spectator. There's been an interesting discourse around the relevance of race when it comes to crime, the relevance of race when it comes to capital punishment, so that discourse has been disturbing to me, but interesting as well.

Davis's supporters compared his case with that of Casey Anthony where the alleged child-killer was set free despite having a body of evidence against her. Casey Anthony is offered a book deal, but Troy Davis is only offered his last meal. Wake up America, our justice system is screwed, wrote Ryan Hunt on Twitter.

Amnesty International condemned the execution. The U.S. justice system was shaken to its core as Georgia executed a person who may well be innocent. Killing a man under this enormous cloud of doubt is horrific and amounts to a catastrophic failure of the justice system, Amnesty said in a statement.

The state of Georgia has proven that the death penalty is too great a power to give to the government. Human institutions are prone to bias and error and cannot be entrusted with this God-like power. The death penalty is a human rights violation whether given to the guilty or the innocent, and it must be abolished, Amnesty said.

Even on social media, many people said that the execution would promote a new civil rights movement to spring up.

Dear AMERICA, we don't know if Troy Davis killed a man...But we know you killed Troy Davis, POPGATES wrote on Twitter, highlighting the alleged uncertainty over Davis' guilt.

American novelist Hari Kunzru also wrote on Twitter: So I wake up to hear they executed Troy Davis. Wonder if most Americans realize how far out of step they are with international norms.

Before his execution, Davis told his family and friends to continue with the protest to clear his name and to prove him innocent. He told the son and the brother of the dead officer that he was innocent and not responsible for the death.

Davis's execution had gained international attention and more than 630,000 people signed petitions urging clemency for him. Though their efforts couldn't save his life, yet his execution has made Davis the poster boy for a global movement to eradicate death penalty.