A United Nations' tribunal on maritime law on Monday asked to hold an international arbitration hearing in The Hague and quashed Italy's request to ask India should to release two marines accused of killing two Indian fishermen about three years ago.

The International Tribunal for the Law of the Sea in Hamburg also directed India to suspend the court proceedings against the two Italian marines in the country, Reuters reported.

The marines, part of a military security team on anti-piracy duty protecting Italian oil tanker Enrica Lexie, have maintained that they mistook the Indian fishermen for pirates and first fired warning shots. Two fishermen were killed in their action.

The incident sparked major protests in south Indian states of Kerala and Tamil Nadu, forcing New Delhi to insist on trial of the two marines in India. All this while, Rome always insisted that it wants the case be taken for arbitration under the United Nations Convention on the Law of the Sea.

The Monday's ruling by the international tribunal was by "15 judges' votes to six that Italy and India should suspend all proceedings which might aggravate or extend the dispute until the arbitration tribunal rules on the issue," tribunal president Judge Vladimir Golitsyn said, accordnig to Reuters.

Indian legal expert and tribunal memeber P Chandrasekhara Rao, who was among the six opposed to the ruling of the international tribunal, said that the verdict was one-sided, PTI reported.

Judge Rao said though the tribunal appeared to have directed its verdict to both parties, "it is actually addressed only to India".

"The measure prescribed by the tribunal, in this case, is entirely one-sided and is not well-founded in law," he said.

In the last three years since the Enrica Lexie shooting incindent, the relations between Italy and India have suffered a major setback. A European Union-India summit planned during Prime Minister Narendra Modi's visit to France and Germany in April was cancelled largely over the Italian marines' issue.