According to the reports, Yemeni forces fired rockets at their vehicle in the al-Sanama district, killing four occupants, the report said. Some Yemeni reports said the Emirati commander had been killed.
Saudi warplanes, meanwhile, carried out fresh airstrikes against Sana'a after dozens of raids in what residents described as the heaviest aerial attacks yet in nine months of aggression.
The neighborhoods of Tabet Zahban and al-Nahdin were targeted in the new attacks.
The al-Mukha and Warazan districts in Ta'izz also came under the Saudi aerial bombings in which an unspecified number of civilians were killed or injured.
The World Health Organization (WHO) called for access to the provincial capital of Ta'izz to deliver humanitarian aid to civilians amid heavy Saudi airstrikes and shelling by pro-Riyadh forces.
The organization said in a statement that all hospitals had been forced to close some services and were overwhelmed with wounded patients.
Five trucks carrying health supplies "urgently needed to be delivered to hospitals" have been prevented from entering the city since December 14, 2015, it said.
"The situation is deteriorating and the needs are huge," Ahmed Shadoul, WHO representative in Yemen, told Reuters.
Separately, Yemen's army forces and their allies retook the al-Thaqaleen area of Ta'izz Province, and an area in the city of Midi in Hajjah Province after clashes with militants loyal to fugitive former President Abd Rabbuh Mansur Hadi.
In Ma'rib Province, at least 20 mercenaries were killed and several others captured on Friday as their push into Hailan in the Sarwah district was repelled.
Two Saudi soldiers were killed in al-Tuwal in the southwestern province of Jizan in retaliatory attacks by Yemeni forces.