ADEN, Yemen, Aug. 8 (Xinhua) -- Armed confrontations broke out between the security units loyal to the Southern Transitional Council (STC) and the Saudi-backed Yemeni government forces in the southern port city of Aden on Thursday, a military official told Xinhua.
"Heavy fighting erupted again and occurred mainly in the areas located near the government's presidential palace in Crater neighborhood," the military source based in Aden said on condition of anonymity.
Witnesses told Xinhua that intense street-to-street fighting began around the government's headquarters and Yemen's Central Bank in Aden.
The tensions extended to include other neighborhoods in Aden following a brief lull that lasted several hours after Wednesday's clashes.
Elsewhere in Aden, an army base of the Saudi-backed Yemeni government fired artillery shells against military locations of STC in Aden's neighborhood of KhorMaksar.
Tanks and heavy armored vehicles of the Saudi-backed Yemeni government forces were deployed in KhorMaksar, according to local residents near the scene.
After Wednesday's clashes, Yemeni Interior Minister Ahmad Al-Maysari declared in a statement that "Presidential Guard forces confronted a group of militants who attacked the Presidential Palace and the Central Bank of Yemen in Aden."
"We will carry out our legal duty as state officials and start securing and protecting all state institutions located in Aden Province," said Al-Maysari.
Hani Bin Buraik, the STC's vice-president, delivered a televised speech calling on the people to march toward the presidential palace and overthrow the Saudi-backed Yemeni government.
"Heavy forces backed by armored vehicles headed toward the palace to kick the government officials linked to the Muslim Brotherhood Islah party out of the city," sources told Xinhua.
The UN Special Envoy to Yemen Martin Griffiths expressed deep concerns over a military escalation in Aden and called on the parties involved to abandon violence and engage in dialogue to resolve differences.
"I am alarmed by the military escalations in Aden, including reports of clashes in the vicinity of the presidential palace. I am also deeply concerned by the recent rhetoric encouraging violence against Yemeni institutions," he said in a statement.
"Escalations of violence will contribute to instability and suffering in Aden and will deepen Yemen's political and social divisions," he said.
Considered Yemen's temporary capital, Aden is where the Saudi-backed Yemeni government has based itself since 2015.
The impoverished Arab country has been locked in a civil war since late 2014, when Houthi rebels overran much of the country and seized all northern provinces, including the capital Sanaa.