File photo shows the immediate aftermath of a Saudi-led strike on Yemen.

Sanaa, July 11 (RHC)-- The Saudi-led coalition has once again broken the terms of a United Nations-mediated truce, killing and injuring as many as 17 people in a cross-border attack on the impoverished country.

The casualties were caused on Sunday after Saudi forces opened fire on a border area in Yemen’s Sa’ada Province, which lies to Yemen’s extreme northwest, a security source told Yemen’s official Saba Net news agency.

Most of the wounded, who have been transferred to a hospital in the city of Razih in the western part of the province, are in a life-threatening condition, the source said.

Elsewhere in the province, the coalition targeted the Shada’a District, killing one person and injuring seven others.  Saudi Arabia launched the devastating war on Yemen in March 2015 in collaboration with its Arab allies and with arms and logistical support from the United States and other Western states.

The objective was to reinstall the Riyadh-friendly regime of former president Abd Rabbuh Mansur Hadi and crush Yemen’s Ansarullah popular resistance movement, which has been running state affairs in the absence of a functional government in Yemen.

While the Saudi-led coalition has failed to meet any of its objectives, the war has killed hundreds of thousands of Yemenis and spawned the world’s worst humanitarian crisis.  The UN-brokered truce between the coalition and Ansarullah, which came into effect in April, was extended for another two months on June 2.

As part of the ceasefire, commercial flights have resumed from Sana'a International Airport to Amman and Cairo, while oil tankers have been able to dock at the port city of al-Hudaydah.

The elusive truce has provided a rare let-up in the Saudi-led coalition’s attacks on the Arab country, even though the coalition has been accused of a series of ceasefire violations.

Also on Sunday, the Yemeni National Salvation Government’s health ministry said a total of 31 people had been killed and 356 others injured as a result of the invaders’ violations of the make-or-break ceasefire.