A ceasefire brokered by the United Nations in war-torn Yemen went into effect Sunday at 11:59 p.m. local time.

Forces loyal to the Yemeni government, backed by Saudi Arabia, and the Shiite rebel Houthi militia agreed to a truce ahead of a planned resumption of peace talks in Kuwait.

The peace talks will be held on April 18.

On Saturday, just hours before the ceasefire went into effect, at least 28 Yemeni soldiers were killed.

Gunmen blocked a main road and opened fire on the soldiers’ vehicles in southern Yemen, local security officials said.

Many of the soldiers, loyal to Saudi-backed President Abdu Rabu Mansour Hadi, were found with their heads cut off, while others had been shot in the head, according to the officials.

No group has claimed responsibility for the attack in Ahwar city in Abyan province.
The al Qaeda-affiliated group Ansar al Sharia, which controls 70% of Abyan province, issued a statement denying involvement.

The United Nations estimates 9,000 casualties, including over 3,000 civilian deaths in the Yemeni conflict from March 2015 to 2016.

The Houthis, a rebel group composed of Shiite Muslims, feel marginalized in the majority Sunni country and have loyalties to an ex-president of Yemen.

The conflict in Yemen is seen by many as a conflict between Sunni-dominated Saudi Arabia and Shiite-majority Iran.

A Saudi-led coalition has been carrying out airstrikes against Houthi militias, who are aligned with Iran. The airstrikes have been condemned by the U.N. human rights chief for killing civilians.