The army targeted the mercenaries in al-Ajashar desert in Jawf, killing and wounding dozens, Saba news agency reported.
In another development, Yemeni artillery units and their allies launched attacks against Tawra al-Bahah area in the southwestern province of Lahij, causing extensive damage in the targeted area.
The attacks came in response to the continued aggression by Saudi Arabia and some of its Arab allies against Yemen, which started in March 2015.
The Saudi-led coalition has been launching deadly airstrikes against the Houthi Ansarullah movement in the past year and a half in an attempt to restore power to the fugitive former president Abd Rabbuh Mansour Hadi, a close ally of Riyadh.
Nearly 14,000 Yemenis, including 4,000 women and children, have lost their lives in the deadly military campaign.