At least fourteen patients and three doctors were killed on Thursday in an airstrike on a hospital in Aleppo, the charity Medecins Sans Frontières (MSF) says. Among those killed in the al-Quds hospital was one of the city's last paediatricians. Local sources blamed the Syrian government or Russian warplanes, but there has been no official comment. Violence in Syria has intensified recently, despite a truce. The violent upsurge comes amid reports that the Syrian army, backed by Russian air power, is gearing up for a major offensive in Aleppo. The escalation threatens to derail the peace talks. On Wednesday, the UN envoy to Syria urged the US and Russia to intervene ‘at the highest level’ to save the talks. On Tuesday an Iraqi military officer reported that Russia is resuming bombing moderate opposition fighters in Syria. President Obama called President Putin, asking him to help ‘press’ Syria to end its airstrikes that violate the ceasefire brokered by the US and Russia in February.