(CNN) More than a dozen people were killed and 60 injured in airstrikes on Wednesday in the last rebel-held area in northwest Syria, according to activists on the ground and the volunteer rescue group known as the White Helmets.

The deaths come after a ceasefire agreement in the province went into effect on January 12, according to the Turkish defense ministry. The deal was brokered by Turkey and Russia.

At least 15 people were killed in strikes on a market and the industrial zone in Idlib city, according to Idlib-based media activist Zaher Jaber. There are reports of people still buried under the rubble.

People search for victims or survivors under the rubble at the popular market in the city of Ariha on Jan. 15, airstrikes on the rebel-held Idlib province.

A resident of Kafra Nbel, a town close to Idlib city, said the area has been targeted twice and aircraft had been hovering overhead throughout the day on Wednesday.

"At least 5 warplanes have been targeting anything moving on the ground," said 22-year-old Mohammad Kafranbel.

Read More