A humanitarian truce in Yemen has failed to take hold after Saudi-led warplanes resumed Tuesday strikes against Yemen rebels whose clashes with loyalists persisted, military sources said.
The five-day truce that began Monday was unilaterally declared by the pro-government Arab coalition to allow the delivery of desperately needed relief supplies.
The coalition, which mounted an air campaign against the Shiite Huthi rebels and their allies in late March, had reserved the right to hit any military movement by the insurgents.
Air strikes targeted rebels north of Aden, Yemen's second city, which was mostly recaptured by loyalists last week after four months of ferocious fighting, military sources said.
Raids also struck rebels in nearby Lahj province, where forces loyal to exiled President Abedrabbo Mansour Hadi have tightened the noose on insurgents in the strategic Al-Anad airbase.
Three air raids targeted a rebel convoy near Sabr, north of Aden, where loyalists had advanced over the past days, military sources said.
Other raids hit a building occupied by insurgents in Jaawala -- also north of Aden.
An overnight air strike hit rebels in Marib, east of Sanaa, witnesses said.
Fighting around Aden has left 28 dead since Monday, including 22 rebels, two civilians and two pro-Hadi southern fighters, said city health chief Al-Khader Laswar.
On Monday, coalition warplanes hit positions of pro-government forces in Lahj by mistake, killing 12 people and wounding 30 others, military sources and witnesses said.
UN chief Ban Ki-moon on Sunday made a plea for all sides to "agree to and maintain the humanitarian pause for the sake of all the Yemeni people".
The rebels said they were not consulted about the ceasefire.