Yemen's Houthi rebels and troops loyal to the internationally-recognised government engaged in a days-long clash near the Saudi border, causing a number of deaths, according to reports.
Houthi rebels launched an intensive assault on the Al-Abtar front in the Al-Jasher area near the Saudi frontier, Arabi 21 reported on Tuesday, citing a military source.
Fighting between the government forces - backed by a Saudi-led coalition - and the Houthi rebels has flared up again since the two sides failed to renew a UN-brokered truce in October.
The Houthi attacks on the positions of the Yemen military's Al-Samoud Brigade in the area are continuing, according to the source.
The number of deaths is not clear, but the commander of the Yemeni government's first battalion Ali bin Naji Shamlan is among the casualties.
The government forces repelled a Houthi attack in the same area on Sunday night, according to local media outlets including Yemen Today.
The leader of Yemen's Houthi rebels warned the Saudi-led coalition on Friday of a possible return to the war if their demands were not met, which includes the withdrawal of coalition forces.
This came weeks after reports of back-channel talks recommencing between the two sides to strengthen an informal ceasefire.
Saudi Arabia intervened in Yemen's war in March 2015, beginning an aerial bombing campaign against Houthi rebels, who had captured the Yemeni capital Sanaa from the internationally-recognised Yemeni government the previous year.
Close to 9,000 civilians have been killed in airstrikes by the Saudi-led military coalition since its involvement in the war, in which it struck key infrastructure, hospitals, civilian venues, and schools in Yemen. Hundreds of thousands are believed to have died in the war, mostly from disease and hunger.