Demonstrators waved the flag of the south and chanted separatist slogans as they took to the streets in the southern port city of Aden on Sunday. Many held portraits of Aidarous al-Zubaidi, a former Aden governor who founded the pro-secessionist Southern Transitional Council earlier this month.
"This massive rally is a clear message for supporting the council. It also expresses the aim of southerners to regain their state," Zubaidi said in a recorded address to the crowd.
Southern Yemen was an independent state until 1990 when it was unified with North Yemen.
Zubaidi was sacked by Yemeni President Abed Rabbo Mansour Hadi in April. Soon afterwards, he set up the self-styled council with a number of prominent southerners, including former minister of state Hani Bin Braik.
The body, chaired by Zubaidi, says it aims to "run the southern provinces" and "represent them inside and outside" the country. Yemen's internationally recognized government has rejected the council, saying it deepens divisions and "will never be accepted."
Sunday's rally is believed to be the largest in Aden since forces loyal to Hadi's Saudi-backed government drove Shiite rebels from the city in 2015. The Iran-allied rebels, known as Houthis, have controlled the capital Sanaa since late 2014, forcing Hadi to move his government to Aden.
The war has left millions of civilians without access to food, clean water or healthcare, and in urgent need of humanitarian aid. A cholera outbreak in the impoverished country has killed more than 200 people, with the World Health Organization warning there could be as many as 300,000 cases of infection within the next six months.
nm/jlw (AFP, AP, dpa)