Thousands have rallied across southern Yemen after an appeal from the last president of the independent south to re-establish the state that ceased to exist twenty years ago.

Ali Salem al-Baid, who led the south to unity with the north in 1990, called for a second day of "southern anger" on Saturday, to coincide with a meeting of international donors to Yemen in neighbouring Saudi Arabia.

"I call on you ... to send a message to our Arab brothers and to the representatives of the international community gathered in Riyadh underlining your rejection of the occupation and your commitment to self-determination," Baid said.

"Our only weapon is our determination to recover our rights, whatever the cost ... we will succeed in regaining our independence."

Brandishing flags of the former south and of Saudi Arabia, crowds took to the streets in the major towns of the provinces of Dhaleh, Lahij, Abyan and Hadramawt.

Businesses in these areas remained closed for fear of clashes with security forces, witnesses and local officials said.

In Abyan, three civilians suffered bullet wounds when police moved to stop demonstrators cutting the highway between the provincial capital of Zinjibar and the south's main city, Aden, witnesses said.

'Yemeni occupation'

Tareq al-Fadhli, a prominent southern secessionist, called on demonstrators in the centre of Zinjibar "to continue your struggle until the south is freed from Yemeni occupation".

Fadhli, a former Islamist who rallied to the southern cause, promised "victory soon" over the Sanaa government of Ali Abdullah Saleh, the Yemeni president.

Protesters also demonstrated in the town of Lauder further northeast, while in Dhaleh, thousands gathered in defiance of a curfew which had  been imposed overnight.

In Lahej, thousands demonstrated in the towns of Hutah and Al-Habilain, and rallies were held in Mukallah, the main city of Hadramawt.

Pro-independence demonstrations have increased in the south in recent months amid a worsening economic situation and complaints of discrimination in favour of northerners by the Sanaa government.

Western governments have been pushing for a sharp increase in aid to Yemen to help Sanaa tackle multiple sources of dissent.