Russia persuaded then Syrian President Bashar al-Assad that he would lose the fight against armed groups led by the Islamist Hayat Tahrir al-Sham, and offered him and his family safe passage if he left immediately, according to three people with knowledge of the situation, Bloomberg reports.

Russian intelligence agents organized the escape, flying Assad out via its air base in Syria, two people said. The aircraft’s transponder was turned off to avoid being tracked, one of them said.

Russian President Vladimir Putin is demanding to know why Russia’s intelligence service didn’t spot the growing threat to Assad’s rule until it was too late, said a person close to the Kremlin with knowledge of the situation.

Russia had bombed opposition fighters initially, in an attempt to push them back and bolster Assad’s forces. But with the Syrian army offering little resistance as rebels seized the city of Hama within days of capturing Aleppo, Russia concluded it couldn’t protect the Assad regime as the opposition bore down on the strategic city of Homs, one of the people said.