An explosion at a dairy in western Yemen killed at least 35 people Wednesday, but the cause of the blast had not been determined.
There were conflicting reports on whether Saudi-led airstrikes or anti-government fighters were responsible.
Officials and witnesses said coalition airstrikes hit near the dairy early Wednesday in the port city of Hodeida. Others reported rebel shelling also hitting the area.
International aid groups expressed alarm a day earlier at the rising number of civilian casualties in Yemen's conflict. The United Nations said 93 civilians had been killed and 364 wounded in the first five days of the now week-old airstrikes.
The Saudi-led bombing campaign is intended to stop Iranian-backed Houthi rebels who control the capital, Sana'a, and have advanced on Yemen's main southern city of Aden.
Meanwhile, Yemen's foreign minister called for the Saudi-led military coalition to send troops to Yemen. In comments to the French news agency, Riyadh Yassin said he called for ground forces because "at some stage airstrikes will be ineffective."
Yassin also said ground forces would cause fewer civilian casualties and would help in aid deliveries.
On Tuesday, U.N. High Commissioner for Human Rights Zeid Ra'ad Al Hussein warned that Yemen was on the verge of "total collapse" and that the situation there is "extremely alarming," with dozens of civilians killed in recent days.
A spokesman for the U.N. High Commissioner for Refugees, William Spindler, told VOA his agency has registered about 250,000 refugees in Yemen.
U.N. spokesman Farhan Haq announced Tuesday the last of the U.N.'s international staffers had left the country and that all of the organization's work in Yemen would be done by several hundred local staff members.