The United States has strongly condemned a Sudanese presidential pardon for a man formerly convicted of aiding four men’s escape from prison, after they were sentenced to death for killing two US embassy staff in 2008. Mubarak Mustafa was previously convicted of assisting the prison break. The pardon “ran counter to previous assurances by Sudan that it would hold accountable all those involved in the murders,” an US embassy statement said on Monday. “In the interests of justice, we urge the government of Sudan to immediately rescind the pardon and return Mustafa to prison to serve out his term,” it added. John Granville, an American working for the US Agency for International Development (USAID), and his driver, Abdelrahman Abbas Rahama, both died after they came under fire in Khartoum on New Year’s Day, 2008. Their killers, along with two co-conspirators, were convicted of murder in 2009 and sentenced to death. In June 2010, the four escaped by burrowing a tunnel, killing a Sudanese police officer and wounding another in the process. One of the men was later recaptured, while a second was believed to have been killed in Somalia in May 2011. The US has threatened to maintain economic sanctions against Sudan, first put in place by President Bill Clinton in 2007 for "counter-terrorism" purposes.