The blasts came as Saudi-led forces conducted more air strikes against Houthi military sites across Yemen and as delegates attending peace talks in Switzerland reported no progress on the second day of a U.N.-sponsored push for a Ramadan truce.
"Four car bombs targeted the political bureau of Ansarullah, the Hashush mosque in the Jiraf district, the Kibsi mosque in the Zira district and the Qubat al-Khadra mosque, causing the martyrdom and injury of dozens," the official told Reuters on condition of anonymity.
Earlier on Wednesday Houthi fighters in central Yemen blew up the home of a senior politician, Abdel-Aziz Jubari, while he was attending the Geneva talks as a member of the exiled government's delegation.
Yemen's Foreign Minister Reyad Yassin Abdulla told Reuters in Geneva that the peace talks had "made no progress".