The incident comes after a suicide bomber for a group affiliated to al-Qaeda in the Arabian Peninsula killed almost 100 soldiers.
«A man was killed and seven others were wounded, one of them seriously,» a medical official told the AFP news agency.
The clashes took place after protesters used rocks to block roads, set tyres alight, and closed shops in the capital of Hadramawt province, witnesses said.
The day of civil disobedience was called by the hardline faction of the Southern Movement, headed by Yemen’s former vice president Ali Salem al-Baid, which advocates independence for the south.
The strike was also observed in other provinces in the south – Lahij and Daleh – while a partial strike was observed in the neighbourhoods of Mansoura and Mualla in Aden, the capital of what was formerly known as South Yemen.
South Yemen was independent before merging with former North Yemen in 1990.
Some factions of the Southern Movement want autonomy for the south, but more hardline members are pressing for a return to complete independence.
The coalition, which began in 2007 as a social protest movement of retired officials and soldiers, gradually became more radicalised.
Residents in Yemen’s formerly-independent south complain of discrimination by the Sanaa government, citing an inequitable distribution of resources since the 1990 union.
The south broke away again in 1994, sparking a brief civil war that ended with the region being overrun by northern troops.
Baid, who was vice president of Yemen when he declared independence in 1994, went into exile two months later when northern troops entered Aden.