Turkey has sent troops and armoured vehicles to reinforce posts in north-western Syria, a monitoring group said Wednesday, amid fears in Ankara of an impending offensive by Syrian forces near the Turkish border.

The Britain-based Syrian Observatory for Human Rights said the Turkish reinforcements, including trucks carrying construction materials and concrete walls, have arrived in parts of Idlib and Hama provinces. 
Turkey has 12 "observation posts" inside Idlib as part of a de-escalation deal with Iran and Russia, according to state news agency Anadolu.
Turkey is concerned that a planned Syrian government offensive against rebels in Idlib province could set off a new wave of refugees heading for Turkey. More than 3 million civilians live in Idlib, which is dominated by Islamist forces, including militants linked to al-Qaeda.
Ankara has for weeks been engaged in diplomatic efforts to prevent a Syrian regime attack on Idlib along its border. Turkey, Russia and Iran are expected hold a summit on Syria on September 7 in Tehran. 
Russian Foreign Minister Sergei Lavrov on Wednesday described Idlib as "the last major stronghold of terrorists."
"So, from all standpoints, this abscess has to be liquidated," Lavrov said in Moscow after talks with his Saudi counterpart, Adel al-Jubeir.
Turkish daily Sozcu separately reported on Wednesday that commando units were deployed to the Syrian border to block a new migration route."
UN Secretary General Antonio Guterres late Tuesday warned that a Syrian government offensive in Idlib would have catastrophic consequences for civilians already suffering due to the seven-year civil war.