Fair warning for Pokemon Go players — stay off military bases.

The Department of National Defence says military police have responded to incidents this month of people trespassing on Canadian Armed Forces bases in Ontario and Nova Scotia while playing the popular smartphone game.

"A Pokemon Go player found on a defence installation who is not authorized to be there could face sanctions including a warning, a citation and fine, or arrest and prosecution," Natasha Leduc, a spokeswoman based at CFB Halifax, said in an emailed statement.

"All Pokemon Go players, members of the defence team or not, are discouraged from pursuing the game in the vicinity or on defence establishments."

Pokemon Go is a smartphone-based game that replicates maps in a virtual realm and fills it with various breeds of collectable creatures called Pokemon. In each country the game has launched, it has become one of the most popular apps ever downloaded.

Guns and jets don't mix with ​Golbat and Jolteon

The game has been credited with encouraging people to go outside and exercise, since the game uses GPS and the only way to explore the virtual Pokemon Go world is to wander the streets in real life.

In the weeks since the app was released in Canada, military police have spoken to civilians playing Pokemon Go at:

CFB Borden (Ontario)

22 Wing North Bay (Ontario)

14 Wing Greenwood (Nova Scotia)

14 Wing Greenwood is home to dozens of aircraft, while 22 Wing North Bay houses an intelligence centre that monitors every aircraft that approaches North America. CFB Borden often conducts training exercises on its land using explosives and ammunition.

Pokemon Go players have been told to stay away from various locations since the game was released, including some hospitals, burial sites and now military bases. (Koji Sasahara/The Associated Press)

"In the interests of public safety, Pokemon GO players must refrain from attempting to access defence establishments without authorization for the purpose of searching for Pokemon," said Leduc.

Officials say they do not expect to ban Pokemon Go for military members, but reaffirm that playing the game on defence establishments is discouraged.

They've also asked staff to keep an eye out for suspicious activity that includes: