Jets believed to be Syrian or Russian on Wednesday struck a main rebel-held city in northwest Syria, killing at least nine civilians, in stepped up strikes on the last rebel bastion in northwest Syria, residents and rescuers said. The air strikes hit Maarat Al-Numan, from which tens of thousands of people have fled in the last two weeks fearing an imminent assault by advancing Russian-backed Syrian troops. Residents said heavy air strikes hit other villages and towns in Idlib province. A strike hit a market in the city of Saraqeb, causing injuries and extensive damage to a main residential area. Earlier air strikes hit rebel positions near a Turkish military post in Sher Maghar village at the edge of Hama and Idlib provinces, where the army has waged a fierce offensive against rebels, according to activists and a senior Turkish security source. There were heavy clashes between Syrian government forces and fighters about 500 meters (yards) from the Turkish observation post, the Turkish source said, adding Turkish soldiers were not affected. Russian and Turkish forces in northern Syria - allies of opposing sides in the civil war but partners in a ceasefire agreement - have been brought closer than ever to direct contact on the ground as the government of Syrian President Bashar al-Assad presses a months-long offensive into the last major rebel stronghold. President Vladimir Putin said on Tuesday that Russia and Turkey had agreed steps to tackle militants in northwest Syria and "normalise" the situation there. Putin and Turkish President Tayyip Erdogan held talks in Moscow after Syrian army troops encircled another Turkish military post in the town of Morek earlier this month. A senior opposition official in touch with the Turkish military said Russian special forces had taken up positions around the Morek outpost to prevent any possible flare-up in the event the Syrian army attacks. "The Russian presence around Morek is to defuse tensions between the Syrian regime and the Turks," the official, who requested anonymity, told Reuters. The Russians would protect the Turkish observation post while preventing the Turkish military from responding to any attack, he added. Turkey has retaliated against previous attacks on some of its 12 posts in Idlib and northern Hama. Turkey has set up 12 observation posts in northwest Syria since reaching a deal with Moscow and Tehran two years ago. Another deal reached last year creates a buffer zone and a ceasefire in the area. Another rebel source in the area said a Turkish military team was touring the Aleppo-Latakia highway in a reconnaissance mission as part of preparations for a new observation post. The deal signed by Turkey and Russia last September called for the reopening of traffic over the strategic M5 and M4 highways, from Aleppo to Hama and Latakia, on the Mediterranean coast, two of Syria's most important pre-war arteries. — Reuters