The Saudi-led coalition jet fighters pounded some sites of Houthi fighters and forces loyal to former President Ali Abdullah Saleh in Sanaa governorate, eyewitnesses said on Tuesday.
They targeted a number of republican Guard camps, they added.
A raft of huge explosions were heard and flames were seen rising from one of the targeted Houthi camps in Sanaa, according to the eyewitnesses.
In Dhamar governorate, some 100 kilometers away from Sanaa, the Arab coalition warplanes bombarded a security building where Houthi militants were hiding.
The air strike destroyed the building and killed and injured a host of Houthi militants.