Rovera, senior crisis response adviser at Amnesty.
But there is “no indication” the coalition has done “anything to prevent and redress such violations,” said Rovera, who is currently in Yemen.
On Wednesday, the United Nations declared Yemen a level-three emergency, the highest on its scale, as aid chief Stephen O’Brien held talks to discuss the crisis.
UN chief Ban Ki-moon also called anew for an “immediate end to the fighting in Yemen to help stem the unfolding humanitarian catastrophe in the country,” a spokesman said.
Wednesday’s statement said that, in addition to some 3,000 Yemenis killed since March, the war has also left 14,000 wounded and displaced more than a million people.
It said “21 million (over 80 percent of Yemen’s population) need immediate help” and that “close to 13 million people are unable to meet their food needs,” while “15 million people have no health care”.
“Outbreaks of dengue and malaria are raging unchecked,” it added.
The International Committee of the Red Cross said in Aden it had started distributing 160 tonnes of food across the front lines to cover the emergency needs of 17,500 people.
“Aden residents have been living under extreme duress for three months,” says Robert Zimmerman, who heads a Red Cross operation there.
“In today’s environment, providing something as basic as food remains a significant challenge, but we will continue to coordinate with all armed groups present in Aden to ensure that emergency aid is delivered impartially to those who need it,” he said.
Unesco, meanwhile, placed Sanaa and the southeastern city of Shibam on its list of endangered World Heritage sites due to the violence.
Sanaa, known for its many Islamic sites and ancient multi-storeyed mud brick buildings, has sustained damage in the conflict, said Unesco.
Shibam, nicknamed the “Manhattan of the Desert” for its high-rise mud brick buildings, is also “under potential threat from the armed conflict,” it added.