Dozens of armoured vehicles were deployed while several roads in the southern port city of Alen were sealed as the protests took place, police said.

The protesters were largely members of the army of south Yemen who were ousted after being defeated by northern forces.

"Protests will continue until all demands are met," said Abu Al Muatari, a spokesman for the retired officers. "We want to feel that we are citizens and partners and not followers."

At least 60,000 southern servicemen were discharged from the army in 1994. Many have not been allowed back into the military.