The Saudi-led coalition intensified airstrikes on Yemen's capital Sanaa on Friday.
It targeted several strategic Houthi weapons depots and explosions of weapons have been shaking the city all day.
Moreover, it targeted military brigades seized by the Houthi militants who ousted the government in late 2014 as well as residences of the former president Saleh.
Residents said security installations including the interior ministry and the national security department were struck as well.
The coalition, which has been bombing the militants since March, also conducted airstrikes in other cities including Marib where fierce battles have been escalating for more than a week.
Separately, well-informed sources said Russian ambassador to Yemen Vladimir Dedushkin came back to the capital Sanaa in a move which comes with Russian efforts to solve the crisis peacefully.
All foreign embassies including Russian and Chinese ones shut down and left Yemen after the Saudi-led military intervention was launched.
Dedushkin was the first foreign diplomat coming back and to Sanaa not to the temporary capital the southern city of Aden.
The Yemeni government returned to Aden two days ago after a six-months stay in Saudi Arabia.