At least 95 countries have active military drone programs, a 58 percent increase from 60 countries over a decade ago, demonstrating the now common usage of unmanned aircraft globally, according to a new study.

The study, done by the Center for the Study of the Drone at Bard College, also says there are at least 21,000 military drones operating worldwide, with the actual number likely more than 30,000.

“Once a novelty, drones have become standard military equipment, spawning a global network of units, bases, and test sites,” writes study author Dan Gettinger, founder and co-director of the center in the preface to The Drone Databook. “Battlefields in Ukraine, Syria, and Yemen, as well as zones of geopolitical conflict such as the Persian Gulf and East China Sea, are increasingly crowded with drones of varying size and sophistication. Whether they are used for intelligence gathering, aerial strikes, artillery spotting, or electronic warfare, drones are a leading contributor to the changing character of modern war.”

The majority of countries with active military drone inventories, 63, have imported all or most of their aircraft, with 49 countries operating at least one type from the U.S., 39 at least one type from Israel, and 32 at least one type made in China, says the 353-page Drone Databook, which is based on a one-year study of open source literature.

The study says at least 10 countries are believed to have used drones to bomb targets and another 30 countries have acquired or are acquiring drones capable of aerial bombing. The countries with unmanned aircraft system aerial strike capability currently are Azerbaijan, Israel, Iraq, Iran, Nigeria, Pakistan, Turkey, UAE, Britain and the U.S., the study says.

“The used of armed drones, particularly by the U.S., has spawned a global debate over the risks that remotely-operated weapons pose to civilians and to the stability of the nation in which the strikes take place,” Gettinger writes. “Many drones that carry weapons are predominantly used for surveillance for spotting targets for manned aircraft.”

Gettinger also says that at least 16 countries have military drones deployed overseas, and eight countries—Iran, Italy, Iraq, Russia, Syria, Turkey, Britain and the U.S.—“are believed to be operating drones in Iraq and Syria. He says the U.S. is believed to also be operating UAS in Afghanistan, West Africa and the Sahel, Somalia, Yemen, the Philippines, the Korean Peninsula, Libya, and Eastern Europe.

Development of new military drones is underway in at least 24 countries, with 36 of the projects for Class III systems, 12 for Class II, and 10 for Class I, The Drone Databook says.

Class I systems weigh less than 330 pounds and range between handheld and larger multi-role UAS. Class II systems are tactical UAS that weigh between 330 pounds and around 1,300 pounds, can remain aloft for 10 hours, have a range between 60 and 120 miles, and have a payload capacity of up to 154 pounds. Class III systems have an endurance of up to 24 hours and can carry payloads weighing about 450 pounds.

There are 171 types of drones in the inventories of the 95 countries combined and of these 107 are Class I systems, 36 are Class II, and 28 are Class III, the study says.

The Drone Databook also includes extensive profiles of each country with active military drone programs.