At least six people were reportedly killed and 32 wounded when Saudi Arabian-led air forces carried out bombings on the Yemeni capital Sana'a on Thursday.

In a statement, the international coalition led by Saudi Arabia said it attacked several "legitimate" targets, including military bases and weapon and ammunition stores controlled by Houthis, an insurgency that Riyadh considers a terrorist organization.

The Arab alliance claimed that the attacks were "precise" and "achieved their objectives," but did not say whether there had been any victims.

The Houthi health ministry said at least six civilians were killed and another 32 people were injured in the bombings.

Four children were among the dead, who were all members of the same family and were in their home in the neighborhood of Al Raqqas, according to a statement from the ministry.

Arab coalition planes of the attacked military targets and residential neighborhoods in the city.

Airstrikes also hit military installations in the neighborhoods of Beit Dehra, Ferija and Samaa, in northern Sana'a, in Nuqom (east), Khawlan (southeast) and in a rebel position on the mountain of Attan, west of the Yemeni capital, witnesses told Efe.

It came two days after Yemeni rebels bombed an oil pipeline in Saudi Arabia with an unmanned aircraft.

Deputy Foreign Minister of Saudi Arabia, Adel Aljubeir, said on Twitter that the “Houthis confirm day after day that they implement Iran’s agenda by sacrificing the need of the Yemeni people for the benefit of Iran.”

He added: “The Houthis are an indivisible part of Iran’s Revolutionary Guard Corps and subject to the IRGC’s orders.

“This is confirmed by the Houthis targeting facilities in the Kingdom.”

The military coalition said in a statement that the drone attacks on Tuesday constituted "serious violations" of international law and "can be considered war crimes."

Hostilities have escalated despite the fact that the Houthis withdrew from three strategic ports on the Red Sea coast last Tuesday, in compliance with the agreement negotiated in December between both sides.

The withdrawal of the ports, including Hudaydah the largest in the country, was a step towards the implementation of the agreements signed in December in Sweden between the two sides.

It was described by the UN as an absolutely necessary movement to be able to resume peace negotiations.

The Yemen conflict broke out at the end of 2014 when the Houthis occupied Sana'a and other provinces of the country and expelled the internationally-recognized president, Abdrabbuh Mansur Hadi.

Saudi Arabia and its Arab allies have intervened militarily in the conflict since March 2015 to try to defeat the Houthis, supported by Iran, and restore Hadi. EFE-EPA