BEIRUT, Lebanon — Raids by Syrian warplanes killed at least 25 people, most of them civilians crowding into a bakery, in the northeastern province of Raqqa on Saturday as government forces continued air attacks on territory controlled by the Islamic State in Iraq and Syria, the extremist Sunni militant group.

The Syrian government has increased airstrikes on the group in recent months after it took over government military outposts in Raqqa in a series of newly assertive attacks.

Government critics, and increasingly some supporters, complain that President Bashar al-Assad’s forces allowed the foreign-led ISIS to gain strength and establish its proto-state over the past year, focusing the army’s attacks more on Syrian-led militant groups whose main aim is to oust the president. ISIS has a broader goal, to remake the Middle East and establish an Islamic caliphate.

ISIS gunmen in Raqqa on Saturday appeared to change their positions and leave their offices on the second straight day of heavy airstrikes, though the government assault there still does not appear to equal the intensity of air campaigns against Syrian-led insurgents in the northern city of Aleppo or the suburbs of Damascus, the capital.