Thousands gathered in Yemen's main southern city of Aden on Tuesday to call for renewed independence for the south 23 years after it united with the north.

Waving the flag of the former People's Democratic Republic of Yemen and portraits of exiled southern leader Ali Salem al-Baid, the protesters gathered at a square in the Khor Maksar district of Aden, an AFP correspondent reported.

"We have vowed that Sanaa will no longer rule us. Get out," they chanted.

"Independence is our goal," read their banners.

After north and south united in 1990, southern leaders led a short-lived breakaway in 1994 that sparked a civil war that culminated in an occupation by northern troops.

The protesters on Tuesday were responding to calls by Baid to commemorate mark the breakaway which he declared on May 21, 1994.

Baid, who now lives in Lebanon, is still campaigning for southern independence despite the participation of the Southern Movement alliance of separatists and federalists, in a national dialogue that began in Sanaa on March 18.