Iran has denied that any of its officers are advising Houthi rebels in Yemen, despite claims that two Iranian military advisers were captured by local militiamen in Aden.
"Iran has no kind of military force in Yemen," Deputy Foreign Minister Hossein Amir Abdollahian said via state broadcaster IRNA.
Rapid advances by the Houthi in Yemen have drawn air strikes from Tehran's regional rival Saudi Arabia.
The International Red Cross (Icrc) have called for an immediate 24-hour ceasefire in Yemen so they can bring in medical aid.
A statement released by the Icrc said: "All air, land and sea routes must be opened without delay for at least 24 hours to enable help to reach people cut off after more than a week of intense air strikes and fierce ground fighting nationwide."
A spokeswoman for the charity told Reuters they were negotiating with all parties and are "hopeful" of getting clearances for aid delivery by Sunday.
Al-Qaida militants in Yemen have freed 300 prisoners from a jail in the coastal city of al-Mukalla in Yemen as it takes advantage of the unrest in the country.
The group was able to capture the city as the county remains in turmoil as a Saudi-led air campaign continues to target Shiite rebels, known as Houthis, and rival groups fight it out across much of the country.
Forces loyal to exiled Yemen president Abdu Rabbu Mansour Hadi continue to clash with Shiite Houthis, loyal to Yemen's deposed leader Ali Abdullah Saleh, in Yemen's second city Aden.
War planes attacked Yemen's capital Sanaa through the night until dawn, residents of the city told Reuters.
"There were planes strikes all through the night and stopped at dawn," said a resident in Sanaa, adding that explosions were heard in an area west of the capital were a government national guard base was located.
There was no detail on whether the planes belonged to the Saudi-led coalition which has launched attacks against Yemen's Shiite Houthi group in support of President Abdrabbuh Mansour Hadi.
Yemen's president Abd-Rabbu Mansour Hadi has left the southern city of Aden under Saudi protection for Egypt, Saudi-owned al Arabiya television said.
He will attend an Arab summit on Saturday. The Dubai-based satellite channel reported: "Hadi leaves Aden to (Egypt's Red Sea resort of) Sharm el-Sheikh under Saudi protection."
Military and security officials in Egypt have said Saudi Arabia and Egypt will lead a ground operation in Yemen against Shiite rebels and their allies after a campaign of airstrikes to weaken them. Three senior officials have told The Associated Press that forces would enter by land from Saudi Arabia and by sea from the Red Sea and Arabian Sea. Other nations will also be involved by Thursday, they said.
The officials would not specify troop numbers or say when the operation would start, only that it would be after airstrikes weaken the rebels and allied forces loyal to former President Ali Abdullah Saleh.
Saudi Arabia has launched air strikes against Houthi fighters in Yemen, the Saudi ambassador in the US has announced.Read the full story ›
The compound of the Yemeni president is being looted as unrest in the country continues.Read the full story ›
A day of bloodshed has seen at least 126 people have been killed in suicide bomb attacks in Yemen. Some 260 people were also injured in the blasts.
The self-styled Islamic State later claimed responsibility - though the White House later cast doubt on that claim.
Four suicide bombers are thought to have taken part, targeting two mosques in the capital, Sanaa.
Warning: ITV News correspondent Emma Murphy's report contains distressing images from the start:
Two suicide bombers have blown themselves up during noon prayers at two mosques in the Yemeni capital Sanaa killing at least 16 people, a medical source has told Reuters.