Two senior army commanders from Saudi Arabia and the United Arab Emirates and two Saudi soldiers were killed in the battle in Yemen, Emirati state media and local sources reported on Monday.
The incident comes as the battle against Iranian backed Houthis intensified only a day before Tuesday's expected peace talks.
Sultan Mohammed Ali al Kitbi, an Emirati officer, and Abdullah al Sahian, a top Saudi colonel, were killed near Taiz, Emirati state news agency WAM reported on Monday.
Saudi state media announced the military commanders’ death accompanied with Quran verses to show mourning.
Media outlets loyal to Houthi militants said they killed the two senior commanders in rocket attacks on the Red Sea coast. The militia also announced their attacks were joined by forces loyal to former president Ali Abdullah Saleh.
For the peace talks with Yemeni President Abd Rabbu Mansour Hadi in Switzerland on Tuesday, Houthis and Saleh's forces are sending representatives to join the awaited talks.
A seven-day renewable ceasefire is scheduled to come into effect on Monday midnight, to coincide with the talks, government officials said.
Two previous attempts at ceasefires, in May and July, failed as a result of alleged breaches on both sides.
Iranian backed Houthis have been battling with the Saudi led coalition since late March, in which the UAE is playing a great role.
As a result of Houthi aggression, Yemeni President Abd Rabbuh Mansour Hadi had to temporarily move to the Saudi capital Riyadh, and formally request Arab states to help “save Yemen” from Houthi expansion.
Saudi Arabia led a military coalition that formally intervened in Yemen in March 25th.
Although Iran did not formally announce its support for the Houthi rebels dissolution of parliament actions against president Hadi, over the years the militant group has received extensive military support from Iran.
War in the country has triggered an unprecedented humanitarian crisis in Yemen. The UN has declared the situation in Yemen to be a level-three humanitarian emergency, the highest on its scale, after about 80 percent of the country’s population fell into dire need of humanitarian aid.
Twenty million people in the country are in need of aid, 13 million are facing food shortages and 9.4 million are having difficulties accessing drinking water.