Fighting broke out in Yemen's key port of Hodeida on Monday even as efforts toward a cease-fire accelerated.
Yemeni military officials accuse the Iranian-backed Houthi rebels of firing in the eastern part of the city. Pro-government forces responded, and Saudi-led coalition jets launched airstrikes.
A Yemeni government official accused the Houthis of firing a rocket toward Saudi territory, saying it failed to reach its target and fell into Yemen.
There has been no comment from the Houthis who said early Monday they would stop drone and missile attacks on Saudi Arabia.
The Houthis also said they would comply with a U.N. call for a cease-fire if the Saudis "want peace."
The Saudis and their coalition partner, the United Arab Emirates, said last week they would end the fighting in Hodeida.
In New York, Britain has circulated a draft resolution to the rest of the U.N. Security Council calling for a cease-fire in Yemen, a halt to attacks on civilian areas, and unhindered access to Hodeida.
The port is under rebel control and is a lifeline for food, fuel and humanitarian aid to the suffering population.
The Saudis have accused Iran of sending arms to the rebels through the port — a charge it denies.
The Trump administration has joined its Western allies in demanding a cease-fire in Yemen. The U.S. has stopped providing refueling services to Saudi coalition aircraft that attack Yemen.
Hilal Khashan, a political science professor at the American University of Beirut, believes a cease-fire will eventually take hold in Yemen, but says each side wants to fire the final shot before it takes effect.
"Usually, before a cease-fire goes into effect, we normally witness an escalation of hostilities and it appears to me that since the fighting continues in Hodeida and the claim that they fired a rocket or a missile into Saudi Arabia that did not reach its target tells us that the Houthis are keen on telling everybody that the last shot was theirs before the cease-fire," Khashan told VOA.
The Houthis seized the Yemeni capital of Sanaa in 2014, forcing the government to flee to exile in Saudi Arabia.
It has since relocated to the southern city of Aden.
Saudi-led airstrikes aimed at driving out the Houthis have killed thousands and wiped out entire civilian neighborhoods, including hospitals.
The fighting has compounded the misery in Yemen, which is also dealing with mass starvation and a cholera outbreak.
Edward Yeranian contributed to this report.