Yemen's defence ministry came under attack from a suicide car bomber and heavily armed gunmen today, killing 52 people and injuring 167 others in a fierce battle in the heart of the capital, Sanaa, the government said, according to Belfast Telegraph.

Among the dead at the ministry complex, which also houses a military hospital, were soldiers and civilians, including seven foreigners - two Germans, two Vietnamese, two Filipinos and one Indian, according to the Supreme Security Commission.

Nobody immediately claimed responsibility for the two-stage assault, but suicide bombings and complex attacks are the hallmarks of al Qaeda.

The brazen morning attack, the deadliest in Sanaa since May 2012, underlined the ability of insurgents to strike at the government as they exploit the instability that has plagued the country, a key U.S. ally, for more than two years. Defence Minister Mohammed Nasser Ahmed was in Washington for talks today, and the U.S. State Department condemned the "senseless killing and wounding of dozens".

The U.S. considers Yemen's al Qaeda branch, known as al Qaeda in the Arabian Peninsula, to be the most active in the world. In recent months, Washington has sharply escalated drone attacks against the militants in the impoverished nation. U.S. forces also have been training and arming Yemeni special forces, and exchanging intelligence with the central government.

The terrorist network gained a major foothold in the south, taking over several towns in the chaos that followed the 2011 uprising that ousted long-time President Ali Abdullah Saleh. The drone strikes and a series of U.S.-backed military offensives helped uproot several key militant strongholds, but al Qaeda continues to fight back.

In an attack blamed on al Qaeda in May 2012, a suicide bomber blew himself up amid troops taking part in a parade rehearsal near the presidential palace in Sanaa, killing 93 soldiers.

The government statement said all the militants who stormed the complex today were killed, but it did not say how many. State TV showed a dozen bodies, identifying them as the attackers. Military helicopters hovered over the site as soldiers and ambulances arrived and gunfire echoed in the streets.

President Abed Rabbo Mansour Hadi, who succeeded Saleh, later met military commanders inside the devastated complex and ordered an investigation into the incident, military officials said.