The army killed and injured tens of mercenaries in Ajasher desert, off Najran, when it repelled two infiltration attempts there, Saba news agency reported.
Two pick-ups loaded with mercenaries were destroyed in Qathami, Ajasher, and all people aboard were killed, the report added.
In the district of Hammad Mouraba in the southwestern border region, the army foiled another infiltration operation, killing scores of them in ambush attacks.
Also, Yemen’s rocketry unit shelled mercenaries' gatherings off al-Sudis area, using Katyusha rockets.
In Jizan, the army pushed back the militants moving toward Qamama hilltop east of Khouba, killing and injuring dozens of them.
Yemen’s defenseless people have been under massive attacks by the coalition for more than three years but Riyadh has reached none of its objectives in Yemen so far.
Since March 2015, Saudi Arabia and some of its Arab allies have been carrying out deadly airstrikes against the Houthi Ansarullah movement in an attempt to restore power to fugitive former president Abd Rabbuh Mansour Hadi, a close ally of Riyadh.
The Yemeni Ministry of Human Rights announced in a statement on March 25 that the war had left 600,000 civilians dead and injured until then. The war and the accompanying blockade have also caused famine across Yemen.