Yemen warned on Wednesday that Iran bears complete responsibility if it does not allow a cargo ship bound for Yemen to be searched.
In a letter to its United Nations mission, Yemen warned that “Iran bears complete responsibility for any incident that arises from their attempt to enter Yemeni waters”.
"The Yemeni government and the coalition forces do not object to aid shipments entering Yemen as long as they obtain the necessary permits from the legitimate government of Yemen and are searched prior to entry," the letter said.
Gulf Arab countries have been bombing Houthi militia and allied army units that control much of Yemen since March 26, as well as inspecting ships entering Yemeni waters in a bid to stop weapon smuggling.
Earlier on Wednesday Iran’s foreign ministry spokeswoman Marzieh Afkham challenged the Arab coalition’s grip on Yemen.
"Permission to inspect the ship carrying humanitarian aid from Iran will not be given to countries participating in the Yemen conflict," Afkham was quoted saying by the Tasnim news agency on Wednesday.
In similar remarks on Tuesday, the head of the Iranian Red Crescent Society (IRCS) said no one has the right to inspect the cargo ship moving in international waters.
Saudi Arabia says Iranian support for militias in Yemen undermines strong government and boosts Sunni militants.
It accuses Tehran of arming the Shia Houthis in Yemen, charges Iran denies. Iran says it only provides assistance for the impoverished in the war-torn country.
The United Nations says 828 civilians, including 182 children, have been killed across Yemen in the conflict.