(CNN) -- Six troops were killed and at least eight others injured when an explosive-laden vehicle exploded in Yemen's southern Aden province on Saturday night, two security officials in Aden said.
Three of the injured troops are currently in critical condition.
The explosion went off at about 8:30 p.m. near a military police checkpoint linking Aden with Abyan province. At least 15 troops were at the scene of the attack, eyewitnesses said.
Fierce clashes took place minutes after the explosion at two different residential areas nearby.
The vehicle was on its way out of Aden when it exploded, witnesses said.
A security official in Aden said the attacks have the hallmarks of extremist groups in Yemen.
This is the second car bomb attack in Aden this year, the first being in July, when a suicide car bomber killed eight troops near a governmental military camp.
Government troops have been fighting extremist militants in neighboring Abyan province belonging to the Ansar al-Sharia group since late May.
Militants still control large portions of Abyan.