Yemeni security officials say that a senior leader of the Islamist Islah Party in the country's south has been killed by a car bomb.

The director general of the Taiz police force, Mutaher al-Shaeiby, says in a statement Tuesday that local party leader Mansour al-Haidary was killed instantly when an explosive device attached to his car door went off.

Al-Shaeiby says police are investigating the assassination and have apprehended a number of suspects.

The Islah party is locked in a bloody confrontation with Shiite Houthi rebels and supporters of ousted President Ali Abdullah Saleh. The Houthis overran the capital Sanaa in September.

The US Embassy in Sanaa condemned the assassination, saying "senseless violence will not resolve Yemen's challenges, and must stop immediately."