The United States on Tuesday offered $10 million for the capture of two fugitive gunmen convicted of the 2008 killings of a US diplomat and his driver in Sudan.
American John Granville, who was working for the US Agency for International Development (USAID), and his driver, Abdelrahman Abbas Rahama, a USAID employee, died in a hail of bullets on New Year's Day in 2008 in Khartoum.
The State Department has put a price of $5 million each on Abdelbasit Alhaj Alhasan Haj Hamad and Mohamed Makawi Ibrahim Mohamed. Makawi was the leader of the attack, while Abdelbasit was convicted of being the second shooter.
The two men are on the run, and believed to be hiding in Somalia, after escaping in 2010 from prison, where they were on death row for the murders.
The State Department also designated the two fugitives as terrorists, freezing any assets they might have in the United States.
"The attack occurred when Granville and Abbas were leaving a New Year's Eve party in Khartoum. Abdelbasit shot Granville and Makawi killed Abbas Rahama during the attack," the State Department said in a statement.
Granville, 33, was credited with working on democracy programs and being a driving force behind the distribution of some 200,000 solar-powered radios across Sudan. Abbas Rahama, 40, had worked with USAID since 2004.
Their killers, along with two co-conspirators, were convicted of murder in 2009 and sentenced to death. But in June 2010, the gang of four escaped by burrowing a tunnel, killing a Sudanese police officer and wounding another.
One of the men was later recaptured, while a second was believed to have been killed in Somalia in May 2011.
Makawi, who was born in 1984 in Sudan, is thought to have had links to Sudan-based terror group Al-Qaeda in the Land of the Two Niles.
Abdelbasit was also born in Sudan, but the exact year of his birth is not known, fluctuating between 1979 and 1983.