SOURCE: BBC (5-21-09)
Others were injured, and dozens of arrests were made. Reports say the police used tear gas and live rounds.
Protests were over poor living standards and alleged discrimination against southern Yemen by the authorities in the north.
Yemen is marking the anniversary of its historic unification in 1990.
Analysts say there has been rising tension throughout the south in the past two years, as the southern independence movement has gained strength.
It began two years ago when former southern military officials, forced into compulsory retirement, demanded higher pension payments.