Saudi-led jets have struck sites in Yemen's rebel-controlled capital, Sana'a,, hours after a temporary UN-brokered ceasefire ended.
The strikes on Sunday targeted military rebel facilities in the eastern and northern parts of Sana'a.
No casualties were reported from the bombing, which rocked the city.
The 72-hour ceasefire ended around midnight on Saturday despite a plea from UN envoy for Yemen, Ismail Ould Cheikh Ahmed, for an extension.
There was no sign that the Saudi-backed Yemeni government or the Iranian-backed Houthi rebels had any interest in extending the truce.
The warring sides repeatedly accused each other of violating the ceasefire after it went into effect at midnight on Wednesday.
The truce was the latest in a series of ceasefires that failed to hold in the impoverished country.
Yemen has been locked in a power struggle between Saudi-backed President Abd Rabu Mansour Hadi and the rebels for more than two years.
The conflict has escalated since March 2015, when Saudi Arabia and Sunni partner countries started an air campaign against the mostly Shiite rebels in Yemen.
Saudis fear that the rebels will give their regional rival, Shiite Iran, a foothold on the Arabian Peninsula.