"Shooting is still going on in various areas of Hadramout province," a witness said.
Analysts and political observers on Tuesday warned of possible clashes in Aden and other major cities in the country's south, where army tanks and soldiers are deployed and dozens of security checkpoints set up.
The Southern Movement leaders in Aden called Tuesday for a general strike, which they described as the first step in "a civil disobedience campaign to boycott the fake election by the northerners," according to a statement received by Xinhua.
The movement said the campaign would include closing stores and schools and blocking main streets in the southern provinces.
A local government official in Aden said on condition of anonymity that "the strike campaign launched by the Southern Movement aims to undermine the social activities and interrupt public life in an attempt to reach political gains."
A witness in Aden said anonymously that "the army forces broke into the stores that were involved in the strike in al-Mansoura district in downtown Aden, triggering severe clashes with pro- secession gunmen."
The northern and southern parts of Yemen were unified in 1990 under a deal between Saleh's ruling General People's Congress party and the Yemeni Socialist Party. However, the deal fell apart later, leading to a crisis between the two sides, which developed into a civil war in 1994.
Separatists who want to end the north-south union are demanding independence, claiming discrimination by northerners and a lack of financial aid.
Meanwhile, militants of the Yemen-based al-Qaida in the Arabian Peninsula (AQAP) have taken advantage of the year-long unrest to bolster their presence in the country's south, including cities in Abyan and Shabwa provinces they seized late in May 2011.
The terrorist group claimed responsibility for killing several senior Yemeni intelligence officers last month in a statement on Monday night, in an act of defiance to the Yemeni authorities in the southern provinces.
The ongoing fighting with al-Qaida militants, which shows the country's fragile security situation, will be a major challenge for the new administration.
Sing, dance and buy for New Year