ADEN, Yemen - The death toll from a suicide bombing that targeted on Sunday a gathering of pro-government troops in Yemen's southern port city of Aden reached 49 dead and more than 39 others injured, a medical official told Xinhua.

The medical source working at Aden's public hospital said in an exclusive phone call that "about 49 dead bodies arrived at our center and more than 39 are still receiving treatment from their injuries in the suicide attack."

An intelligence source said that a suicide attacker detonated his explosive belt at a crowd of pro-government forces who gathered to receive their salaries near the house of Brigadier Nasser Anbouri in Aden's neighborhood of KhorMaksar.

Earlier, a military source anonymously told Xinhua that an attacker dressed as a soldier sneaked into a gathering of pro-government troops and then blew him up causing a huge blast that left 32 soldiers killed.

Yemeni security forces sealed off the area and blocked the roads leading to the scene, while ambulances and police vehicles evacuated the killed and wounded people to the city hospitals, the Yemeni sources said.

The Yemen-based affiliate of the IS terrorist group has frequently targeted military bases where crowds of pro-government soldiers gather.

Sunday's suicide attack comes less than two weeks after a similar attack claimed by the Yemen-based affiliate of the Islamic State group struck an army base near Aden's international airport, leaving 50 pro-government soldiers killed and more than 40 others injured.

The southern port city of Aden is the headquarters of Yemen's internationally-backed President Abdu-Rabbu Mansour Hadi and his government.

Aden witnessed several well-planned assassinations and armed attacks after Saudi-backed forces drove the Shiite Houthi rebels out from the strategic city in July 2015.

However, the newly-trained anti-terrorism troops supported by UAE armored vehicles made substantial achievements in recent weeks, disabling several explosive material factories used by terrorists to manufacture car bombs in Aden.

In addition, several commanders of the Yemen-based al-Qaida branch were captured in the successful raids conducted by the UAE-backed Yemeni forces in Aden and neighboring provinces.

Yemen, an impoverished Arab country, has been gripped by one of the most active regional Al-Qaida insurgencies in the Middle East.

The Yemen-based Al-Qaida in the Arabian Peninsula (AQAP), also known locally as "Ansar al-Sharia," emerged in January 2009, claiming responsibility for a number of terrorist attacks against Yemen's army and governmental institutions.

The AQAP and the IS-linked terrorists took advantage of the security vacuum and ongoing civil war to expand their influence and seize more territories in southern Yemen.

Security in Yemen has deteriorated since March 2015, when war broke out between the Shiite Houthi group, supported by former President Ali Abdullah Saleh, and government forces backed by a Saudi-led Arab coalition.

Over 10,000 people have been killed in ground battles and airstrikes since then, many of them civilians.