Iran on Friday condemned air strikes in Yemen by a coalition led by its regional rival Saudi Arabia that are reported to have killed 20 civilians.

"Sadly, the indifference of the international community and continued sale of all kinds of arms to Saudi Arabia have emboldened this regime in its attacks on the oppressed and defenceless people of Yemen," foreign ministry spokesman Bahram Ghasemi said, quoted by state broadcaster IRIB.

The Saudis "continue their endless violations" while "the meaningful silence of some Western countries on the massacre of innocent people will undoubtedly make them more hated in the eyes of the world and a partner in the child-killing regime's crimes," he added.

According to a Yemeni government official, the Saudi-led coalition air raid in the Red Sea port of Hodeida on Wednesday night killed 20 civilians.

He said the residential neighbourhood was "probably hit in error".

Coalition spokesman General Ahmed Assiri said rebel leaders had been the target. He said the alliance had no information on casualties because it is not present on the ground there.

The strikes came with Riyadh facing mounting international scrutiny over civilian casualties in its 18-month campaign against Shia Houthi rebels and their allies in Yemen.

Shia Iran strongly opposes the Saudi-led military intervention but denies arming the Houthis, who control large parts of the country including the capital Sanaa.