A British Airways pilot believes that a drone, also known as a small unmanned aircraft system (sUAS), struck the front of the Airbus A320 during landing at London’s Heathrow Airport on Sunday, April 17. The aircraft landed safely and no damage was reported. An investigation of the incident is ongoing and no arrests have been made.

Following the drone strike, the United Kingdom’s Civil Aviation Authority (CAA) issued a statement reminding drone users that it is unacceptable to fly drones near airports and those who fail to follow rules can face severe penalties including imprisonment. Although a similar incident has not been reported in the U.S., the FAA can impose significant penalties—both civil and criminal–for violations of UAS regulations.

Unlike in the U.S., where drone users must register their drones weighing more than 250 grams and less than 25 kilograms, the U.K. has no system in place to register and track drones. The U.K also currently only requires sUAS owners doing “aerial work” as well as those seeking to fly a sUAS in congested area to obtain special permission from the CAA. Not surprisingly, following Sunday’s incident, there have been calls for increased regulation of drones in the U.K., including from members of parliament.

Although the likelihood of drone vs. aircraft collisions may be low, given the numerous reported incidents and near-misses in recent months, increased regulation of UAS around the world is on the horizon.