Three Vietnamese tourists got off with a warning after they were arrested for flying a camera drone in front of the Royal Palace on Saturday.

Tran Minh Hung, 27; Nguyen Drun Anm, 23; and Nong Minh Buong, 24, were detained on Saturday, given a lecture on the capital’s drone ban, then released on the same day.

Police have confiscated the trio’s drone, which contained pictures of the landscape surrounding the palace.

“We just educated them because they are tourists who do not know about the laws and restricted areas in Cambodia,” said Seang Sen, director of general security at the Ministry of Interior.

In February 2015, Phnom Penh Municipal Hall banned the use of camera drones in the capital, citing privacy and public safety concerns.

The ban was issued shortly after a German man flew a drone into the Royal Palace and startled the Queen Mother, who was exercising.

The rule, however, has since been broken on multiple occasions. In June, US and French nationals were arrested for flying a camera drone over Prime Minister Hun Sen’s house and taking pictures.

A week ago, a Chinese national was briefly detained after flying a drone over the Royal Palace. All three were warned and released.