Prominent Syrian activist and radio host Raed Fares has been shot dead in the town of Kafranbel in the rebel-held province of Idlib, BBC reported on Saturday. Fares, who founded an independent radio station called Radio Fresh that broadcasts from rebel-held areas, was a trenchant critic of both President Bashar al-Assad and his Islamist opponents.

Fellow activist Hamoud Jneed was also murdered along with Fares on Friday morning by unidentified gunmen. The attackers waited in a van outside an office that the two men shared, followed them through the market, and then shot at them when they neared their car, reported The Guardian.

Salman, a 33-year-old mathematics teacher, who witnessed the attack, told the Middle East Eye website that the attackers “fired shots from a machine gun, before speeding away”. Jneed died on the spot while Fares died of his wounds in a hospital.

When the uprising against Assad’s regime started in 2011, Fares designed powerful posters for demonstrations. “Syria has two conflicting parties: people who try to survive, and a regime that tries to crush them,” read one of his first banners. The posters and Fares’ activism drew international attention on social media and led to Kafranbel being called “the conscience of the revolution”.

His posters and banners targeted Assad, his allies Iran and Russia, Western countries that Fares accused of selling out ordinary Syrians, and the various armed groups who had emerged out of the chaos.

In his last tweet, on September 21, Fares wrote about a demonstration against “Russia, Assad and all kinds of terrorism”. He also posted a picture with his two sons at the rally against a potential offensive by the government and their allies.