Somali pirate gangs have stepped up hijacking attacks on vessels in Indian Ocean and Gulf of Aden [GALLO/GETTY]

US officials have arrested an alleged Somali pirate who is said to have been the chief negotiator in a yacht hijacking that left four Americans dead.

The killings in February off the coast of Somalia were one of the deadliest piracy incidents in recent years.  

Mohammad Saaili Shibin is the first alleged pirate to have been arrested on-shore in Somalia. He was brought to the United States in early April, but was indicted by a federal grand jury earlier for his alleged role in the killings.

The Wall Street Journal reported that US forces, with the help of Somali army, had apprehended the alleged pirate on land. It was the first time that the US had carried out a similar operation on-shore.

'Significant breakthrough'

Neil MacBride, US Attorney said "The arrest of Mohammad Shibin is a significant breakthrough in the United States' battle against Somali pirates."

"Today marks the first time that the US government has captured and charged an alleged pirate in a leadership role - a hostage negotiator who operated in Somalia.

"We hope that this indictment will strike at the heart of the piracy business and send a strong message to all pirates that they are not beyond the reach of the FBI, whether they board the ships or remain on-shore in Somalia," he said.

Shibin has been charged in US federal court in Norfolk, Virginia, over the alleged pirating of an American yacht, and the taking of four US citizens hostage.

All four hostages were later killed in a botched rescue attempt.

According to the indictment, Shibin researched over the Internet who the hostages were to try to determine how much ransom to demand and the identity of their family members so he could contact them about a ransom.

The four slain Americans were Jean and Scott Adam of California and Phyllis Macay and Bob Riggle from Seattle. They were sailing their yacht, 'The Quest', off the coast of Oman in the Indian Ocean when the pirates attacked the vessel.

The US justice department officials said the defendant was identified by his co-conspirators as the person in Somalia responsible for negotiating the ransom.

Several indictments

Last month, the justice department indicted several other suspected pirates on charges related to the same hijacking.

Pirate gangs operating off the coast of Somalia have stepped up hijacking attacks on vessels in the Indian Ocean and the Gulf of Aden, making tens of millions of dollars in ransom money by seizing ships, including oil tankers.

In this incident, a group of pirates seized the yacht and were negotiating with the US military to release the couples when a pirate fired a rocket-propelled grenade at the guided-missile destroyer USS Sterett.

Gunfire then broke out inside the pirated vessel, prompting the US military to send American special forces to board the ship. The US military has said the pirates shot the hostages before American troops boarded the yacht.

US troops killed two pirates as they boarded the boat. Another two were found dead when special forces arrived but they were not killed by US forces, the military has said.

Thirteen Somalis and one Yemeni were brought to Norfolk a month ago to face charges of piracy, conspiracy to commit kidnapping and use of firearms during a crime stemming from the incident.

Source: Agencies