The U.S. State Department on Tuesday offered 10 million dollars in rewards for information on two killers of two U.S. Agency for International Development (USAID) employees.

Abdelbasit Alhaj Alhasan Haj Hamad and Mohamed Makawi Ibrahim Mohamed, along with three others, were convicted in Sudan for killing John Granville, a USAID diplomat, and Abdelrahman Abbas Rahama, a Sudanese national employed by the aid agency, in Sudanese capital of Khartoum on Jan. 1, 2008.

The pair were gunned down when they were leaving a New Year's Eve celebration in their car, and five men were tried and convicted in 2009 by a Sudanese court for their involvement in the murders.

Four men, including Abdelbasit and Makawi, were sentenced to death but managed to escape from prison on June 10, 2010, the State Department said.

It said one convict was recaptured later, and another reportedly killed in Somalia in May 2011, but Abdelbasit and Makawi remain at large and are believed to be in Somalia.

The department described Makawi as a man with ties to the Sudan- based terrorist organization al-Qaida in the Land of the Two Niles, a group it said conspired to attack other U.S., Western and Sudanese targets.