Three Yemeni children were killed in an explosion caused by a projectile in the central province of Marib, according to a local observatory.

The Yemeni Landmine Monitor said the three siblings were killed when the projectile exploded in the town of Harib in Marib on Friday.

No details were provided about the group behind the attack and there was no comment from the Yemeni authorities.

On Wednesday, the observatory said that 36 people had been killed as a result of landmine and bomb explosions across Yemen last month.

At least one million mines have been planted across war-torn Yemen, according to previous statements by Yemeni officials.

Iranian-aligned Houthi rebels have for months stepped up attacks to take control of oil-rich Marib province, one of the most important strongholds of the legitimate government and home to the headquarters of Yemen’s Defense Ministry.

Yemen has been engulfed by violence and instability since 2014, when Houthi rebels captured much of the country, including the capital, Sanaa.

A Saudi-led coalition aimed at reinstating the Yemeni government has worsened the situation, causing one of the world’s worst man-made humanitarian crises, with nearly 80%, or about 30 million people, needing humanitarian assistance and protection and more than 13 million in danger of starvation, according to UN estimates./aa