Sana'a, Yemen - A Yemeni army officer was killed and two of his bodyguards injured in an ambush by suspected Shiite rebels in the restive north-western province of Saada, the Defence Ministry reported Wednesday.

The ministry said armed members of the outlawed al-Houthi group opened fire at a military car carrying Colonel Aidarous Thabit al-Sabri and his four bodyguards on a road between Saada and the capital Sana'a early on Tuesday.

Saada is located on the border with Saudi Arabia, some 230 kilometres north-west of Sana'a.

Al-Sabri, a commander of an army contingent, was killed instantly, the ministry said in a statement.

It said two of the assailants were identified by authorities and that security forces were sent to the area to hunt them down.

The rebels, who are led by the Shiite rebel leader Abdul-Malik al-Houthi and are knows as Houthis, have yet to claim responsibility for the attack.

Tensions have been rising in recent months between Houthis and the army in Saada since last July when Yemeni President Ali Abdullah Saleh declared the conflict over.

Fierce battles between the rebels and army forces have left hundreds of soldiers and insurgents dead since the fighting erupted in 2004, after the rebel group, Believing Youth, was founded by Shiite rebel leader Hussein al-Houthi.

Hussein, the eldest brother of the current group leader Abdul- Malik, was killed by the army in September 2004.

Authorities have accused the rebels of trying to reinstall the rule of imams, which was toppled by a republican revolution in northern Yemen in 1962.

The Houthis belong to the Zaidi sect, an offshoot of Shiite Islam.(dpa)