KABUL, Afghanistan — Attacks on Afghan schools tripled from 2017 to 2018, a Unicef report said Tuesday, as the Taliban and other extremist groups in Afghanistan continue to wage a campaign of violence against so-called softer targets, far from the battlefield.

The number of attacks increased to 192 from 68, a surge not seen since 2015, according to the report by the United Nations agency for children. The number of children not attending school also increased last year for the first time since 2002.

It is yet another sign of the deteriorating security situation across Afghanistan. To some Afghans, the report offered concrete evidence that the repressive Taliban regime is again on the rise, even as the United States attempts to negotiate a peace settlement with the group.

Nooria Nazhat, a spokeswoman for the ministry of education, said the government did not have any specific statistics to back up the Unicef report. But she added: “Every week we have a report about schools getting attacked in Afghanistan.”