Security forces and armed southern separatists clashed Monday in Yemen's port city of Aden, witnesses said, as rising tensions in the country's south threatened to disrupt Tuesday's presidential vote.
Troop reinforcements with dozens of armoured vehicles arrived in Aden from the capital Sanaa late Sunday to reassure voters after hardline members of the separatist Southern Movement threatened violence on election day, security officials said.
Witnesses said government troops and armed separatists exchanged fire mid-morning Monday in the Mansoura neighbourhood of Aden, a stronghold of the movement, where a mass protest against the poll was expected later in the day.
There were no immediate reports of casualties.
Authorities are taking pre-emptive action, with a security official saying that police on Sunday and Monday had carried out "arrest raids on armed hardliners" from the Southern Movement trying "by force to prevent citizens from participating in the elections."
"These elements are trying to create a state of fear among citizens by spreading rumours that February 21 (election day) will see acts of violence," the official told AFP, speaking on condition of anonymity.
An activist from the movement told AFP that 19 of their members "were arrested Sunday night by police" at a checkpoint in northern Aden as they tried to reach Martyrs' Square, a focal point for separatist protests in Aden.
Attacks against electoral offices and polling stations have increased in recent days.
On Sunday night, southern militants fired a rocket propelled grenade at an election base in the Khour Maksar neighbourhood of Aden, a security official told AFP, adding that there were no casualties.
Also Sunday, three soldiers were wounded in a clash with southern separatists near a polling booth in the southern Lahij province.
The Southern Movement has called on its supporters to boycott Tuesday's election in which vice president Abdrabuh Mansur Hadi will be the only candidate.
A hardline faction from the separatist movement on Saturday called for a day of "civil disobedience" to disrupt the poll.
Hadi will become president for a two-year interim period as stipulated in a Gulf-brokered deal signed by President Ali Abdullah Saleh after months of protests against his 33-year-rule.