Warplanes of a Saudi-led coalition Friday launched raids on sites used by Houthi militants and factions loyal to former Yemeni president Ali Abdullah Saleh just hours before a UN-brokered humanitarian pause starts.

The air attacks hit a site controlled by the Republican Guard in Sanaa.

Meantime, a site of the Yemeni military engineering corps was targeted in Sa'wan village in western central Yemen.

The UN has announced an unconditional week-long humanitarian ceasefire to come into force as of Friday as 25 million people are believed to be in need of emergency aid.