Saudi-led air strikes on a prison camp run by rebels in Yemen killed 12 people and wounded 80 on Wednesday, the rebels' Al-Masirah TV reported.
Russian air strikes killed 21 civilians early Wednesday in a village held by the Islamic State group near the Euphrates River in eastern Syria, a monitor said.
Saudi Arabia and its allies struck a day after Saleh's son vowed to lead a campaign against the Iran-aligned Houthis.
Russia's Defence Ministry denied on Monday that Russian war planes had carried out deadly air strikes on a village in Syria's Deir al-Zor province that had killed dozens of civilians, the Interfax news agency reported.
Syrian regime and Russian air strikes on Sunday killed 57 civilians, among them 19 children, in rebel-held Eastern Ghouta region and in a village held by the Islamic State group in Syria's eastern Deir Ezzor province, a monitor said.
The deaths were the result of the latest bout in an escalating cycle of tit-for-tat attacks between regime forces and the rebels holding the enclave on the Syrian capital's eastern outskirts.
The Syrian army backed by Russian jets on Wednesday stepped up shelling and air strikes on a besieged rebel-held enclave in Damascus a day after rebels stormed an army base in the area, rebels, a war monitor and residents said.
Iraqi forces on Friday entered Al-Qaim, the main town in the Islamic State group's last bastion in the country, military commanders said.
Former residents and the Syrian Observatory for Human Rights said there were heavy aerial strikes on eastern Syria's largest city as troops pushed towards the Hay al Umal area.