Ayatollah Ali Khamenei said Saudi Arabia would not emerge victorious from the war in Yemen.
Iran has repeatedly urged a halt in the air strikes and called for dialogue in Yemen, but Supreme Leader of the Islamic Revolution Ayatollah Ali Khamenei’s comments are the most strong position of Tehran about the more than 2 weeks aggression in Yemen by Saudi Arabia and its Arab allies.
"The aggression by Saudi Arabia against Yemen and its innocent people was a mistake... It has set a bad precedent in the region," Supreme Leader said in a televised speech.
"This is a crime and genocide that can be prosecuted in international courts," Leader added. "Riyadh will not emerge victorious in its aggression."
In same day but in separate location Iranian President Hassan Rouhani also criticized the coalition assembled by Riyadh, saying it was repeating errors committed in other parts of the Arab world.
"You tried it in Lebanon, and realized your mistake. You tried it in Syria, and realized your mistake. You realized your mistake in Iraq. You will realize soon that you also made a mistake in Yemen," he said.
Houthi fighters and troops loyal to it entered the provincial capital of the mainly Sunni Muslim Shabwa province in eastern Yemen on Thursday, residents said.
Local tribal chiefs and security officials facilitated the entry of the Houthi forces to Ataq, where they took control of local government buildings and security forces compounds, according to residents.
It was the first time the Houthis, from the Zaidi branch of Shi'ite Islam, and forces loyal to it had entered the city, where the fiercely Sunni Muslim Awlaki tribe comes from.
The takeover brings them closer to Yemen's most prized economic asset, the Belhaf gas facility and export terminal, on the Arabian Sea about 160 km (100 miles) to the southeast.
Earlier in the day, residents of al-Siddah district in central Yemen said they woke with al Qaeda attack to the city.
They said a group of al Qaeda militants led by a local commander known as Ma'moun Hatem, took over the district at night.
Al Qaeda in the Arabian Peninsula (AQAP), one of the most active branches of the network founded by Osama bin Laden, has exploited the security vacuum to entrench itself further in the country's remote eastern reaches.
Last week, AQAP captured the eastern port city of Mukalla. Residents said tribal fighters were deployed to push AQAP out, but that parts of the city were still under AQAP control.
The Houthis, who captured Sanaa in September, have said their advance beyond the Yemeni capital is aimed at fighting al Qaeda.
Warplanes from the Saudi-led coalition struck military targets and weapons stores near the capital under Houthi control, as well as northern areas near the border with Saudi Arabia and in Yemen's south, local officials said on Thursday.
They also targeted a playground where the Houthis are gathered east of Aden's al-Mansoura district, and dropped military supplies to tribal fighters allied to former president Hadi in the Radfan area, north of Aden, local officials said.
Aid agencies have been trying to fly emergency supplies into the country, already one of the poorest in the Arab world, but have been delayed by logistical problems and negotiations needed to fly planes into the country amid the fighting, NDTV reports.