At least four people have been killed in raging battles between government forces and secessionist fighters in Yemen's southern port city of Aden.

Yemen's Prime Minister Ahmed bin Dagher accused southern separatists of attempting a coup after fighting erupted. The two sides in Aden are supported by countries within the Saudi-led coalition that are fighting the Houthi rebels.

Fighting has also intensified in the city of Taiz in central Yemen, prompting international aid organisations such as OXFAM to close down their offices.

Al Jazeera's Osama Bin Javaid reports.