Children were among at least 14 people killed in an air strike in a residential neighbourhood of Yemen's capital, Sanaa, witnesses and medics said.The attack destroyed two buildings on Friday in the southern district of Faj Attan, leaving people buried under debris, they said.Mohammed Ahmad, who lived in one of the buildings, said he was among residents who had taken nine bodies to a hospital."We extracted them one by one from under the rubble," he said. "Some of them were children from a single family."READ MORE: Saudi Arabia's war in Yemen 'a strategic failure' "When the rocket hit, one of the buildings was immediately destroyed which caused the building next door to collapse too. Some residents got out, but others were trapped."The death toll was feared to rise further as rescuers pull more victims from the rubble.The air strikes, believed to be carried out by the Saudi-led coalition, come amid escalating tensions.Separate rallies were heEarlier this week, coalition fighter jets struck a hotel in Arhab, north of Sanaa, killing at least 41 people.UN humanitarian chief Stephen O'Brien last week described the conflict between the Saudi-backed Yemeni government and the Houthis as a "deplorable, avoidable, completely man-made catastrophe" in a briefing to the UN Security Council.The number of air raids per month is now three times higher than last year, and monthly reports of armed clashes are up 50%, he said.The conflict in Yemen has escalated dramatically since March 2015, when Saudi-led forces launched a military operation against rebels.Since fighting began, more than 10 000 people have been killed, and millions have been driven from their homes.The country is also facing a health crisis, with close to 2 000 people having died from cholera since April, more than half a million people infected, and another 600 000 expected to contract the infection this year.