Iran's Supreme Leader Ayatollah Ali Khamenei has called his country's missile strike on US targets in Iraq a "slap in the face" for the United States and said that Washington's troops must leave the region.

Khamenei's televised remarks on Wednesday came hours after the missiles were fired at the Ain al-Asad base in Anbar province and a facility in Erbil amid escalating tensions between Washington and Tehran following the US assassination of Iranian military commander Qassem Soleimani in Iraq last week.

The Iraqi military said in an online statement that 22 missiles were launched on the two sites between 1:45am and 2:15am on Wednesday (22:45 GMT and 23:15 GMT on Tuesday). Two of the 17 missiles targeting Ain al-Asad base did not go off, the military said, while the five missiles on Erbil all targeted coalition headquarters.

The supreme leader had pledged severe retailiation against the US air strike that killed Soleimani as well as Abu Mahdi al-Muhandis, the deputy commander of Iraq's Popular Mobilisation Forces (PMF, or Hashd al-Shaabi), an Iran-backed umbrella organisation, among others.

"Last night we slapped them in the face," Khamenei said in his speech in the capital, Tehran, adding that military retaliation was not enough.

"What is important is that the corrupt presence of the US in this region should come to an end."

Khamenei was addressing a large crowd, many of whom were holding pictures of Soleimani, who headed Iran's Quds Force, the overseas arm of the elite Revolutionary Guards Corps.

Soleimani was buried in the "martyrs section" of a cemetery in his hometown of Kerman after three days of funeral processions that saw his coffin travel to various cities across the country and huge crowds paying respects to him.

Before Soleimani's burial, a stampede erupted at the procession in Kerman, killing more than 50 people.

"I'm very sorry for that and I'm very sad for that," Khamenei said, referring to the stampede.

"I would like to express my condolences to their families … I wish their spirits, their souls, join the soul of Soleimani," he said.

aljazeera