Houthi fighters advanced into key positions in the strategic port city after pro-government forces withdrew.
Violent explosions have rocked the northern neighbourhoods of Sanaa hours after the Saudi-led military coalition said it was launching air raids on “legitimate” Houthi military targets in the Yemeni capital, Reuters reported.
The Saudi-led coalition earlier asked civilians not to gather around or approach potential targets, Saudi state TV reported on Tuesday.
The raids targeted two military sites, residents told Reuters.
The air raids come days after the Houthi movement said on Saturday it had aimed 14 drones at several Saudi Arabian cities, including at facilities operated by Saudi oil giant, Aramco, in Jeddah.
Houthi-run Al Masirah TV confirmed the attacks that took place early on Tuesday, saying at least three air raids have struck parts of Sanaa.
One attack resulted in a fire breaking out in a plastics factory, while the other attacks have damaged several residential homes, according to the Al Masirah TV report.
There have been no immediate reports of deaths or injuries.
The coalition said the operation targeted “secret ballistic missile sites”, adding it had destroyed a “high value ballistic missile target” in the Thahban neighbourhood, north of the capital.
It added that the attacks “comply with international humanitarian law and the principle of self-defence”.
The move comes hours after the kingdom blamed the Houthis, who control the capital and vast swaths of northern Yemen, for turning Sanaa airport into a military base to launch attacks into Saudi Arabia.
Meanwhile, the Houthis are pressing an offensive in Marib, the internationally recognised government’s last northern stronghold, as well as in other areas in Yemen.
The Iran-linked Houthis have repeatedly launched cross-border attacks on Saudi Arabia using drones and missiles since the coalition intervened in Yemen in March 2015 after the Houthi movement ousted the internationally-recognised government from the capital.
The conflict, seen as a proxy war between Saudi Arabia and Iran, has been in military deadlock for years.
According to the UN Office for the Coordination of Humanitarian Affairs, the conflict has killed more than 233,000 people.
Efforts led by the UN and US to engineer a ceasefire in Yemen have stalled.