Barakat is the most senior state official to die at the hands of insurgents since the 2013 coup.
Tarek Dergoul was released in 2004 after being held for two years without charge at Guantanamo Bay.
Militants drove a truck laden with explosives into a crowded checkpoint.
US Army Colonel Christopher Garver said the battle for the city had already started.
Gunmen stormed a Catholic retirement home in Yemen's port city of Aden on 4 March.
Aircraft can simulatneously drop 32 tons of bombs and will replace a fleet of Rockwell B-1 Lancer supersonic planes.
Senior jihadi behind IS online propaganda machine reportedly killed in airstrike
Police seized 'biological weapons' from terror suspects, claims interior ministry.
Italian intelligence officials said they were working to secure the pair's release.
The military uniforms were labelled second-hand clothes and disguised as humanitarian aid to Syria and Iraq.
'Easily influenced' man later died in suicide bombing in Iraq.
UK Parliamentary committee told Islamic State makes up to £14m a month laundering stolen money into Middle East markets
Six soldiers were killed in clashes as Islamic State militants attempt to overrun army garrison.
Islamic State's Cyber Caliphate Army promised to take down Google, but mistakenly targeted small Indian firm.
Jurgen Todenhofer said disagreements between President Bashar al-Assad and opposition sparked the conflict.
Iraqi government concludes deal with Trevi group to prevent catastrophic collapse of facility on Tigris River.
Jordanian authorities say they foiled an Islamic State plan to attack military and civilian targets.
Detainee will be handed over to Iraqi officials after interrogation, US officials said.
Philip Breedlove says Islamic State militants 'spreading like cancer' among refugees.
The cessation of hostilities has brought some respite to civilians, particularly from air strikes.
Defence secretary also says he is concerned by IS's growing strength in Libya.
The blast occurred about 60 miles (90km) north of Iraqi capital in the town of Muqdadiyah.