A military source said Yemeni forces have managed to take full control over one of the Saudi military bases in Najran, the Arabic-language al-Ahed news website reported.
In the operation mounted by the Yemenis, a number of Saudi servicemen were killed or injured and heavy damages were inflicted upon the Saudis.
Another military source said Yemeni troops managed to capture several military bases in Jizan, killing and injuring dozens of Saudi forces there.
The attacks were carried out in retaliation for the regime's ongoing airstrikes targeting Yemeni civilians.
The developments came as Yemen’s defenseless people have been under massive attacks by the coalition led by the Saudi regime for more than two 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 launching deadly airstrikes against the Houthi Ansarullah movement in an attempt to restore power to the fugitive former President Abd Rabbuh Mansour Hadi, a close ally of Riyadh.
More than 12,000 Yemenis, including thousands of women and children, have lost their lives in the Saudi onslaught on the Arabian Peninsula country.