Police will control drones more tightly to curb their improper use as their popularity spreads. (Photo Creative Commons/Macomb Paynes)

The Central Investigation Bureau (CIB) is stepping up its suppression of illegal drone activities, saying many drone enthusiasts don't realise they are required by law to seek permission before flying their toys.

Aside from its bid to regulate drone flying, the CIB also plans to acquire a modern anti-drone device for dealing with drones which stray into prohibited zones, said Pol Lt Gen Thitiraj Nhongharnpitak, chief of the CIB.

Large numbers of drones equipped with cameras are being flown without permission, sometimes straying into prohibited areas and controlled air space.

Their unauthorised use has led to security and privacy concerns as enthusiasts, and some with less honourable intentions, using the aerial flying vehicles to snoop on neighbours or sensitive military installations.

Drones, already popular with tourists and hobbyists, are also widely used in agriculture, parcel delivery, construction, surveying and mapping. They are also used to deliver medical supplies in remote areas as well as collect blood samples.

They are popular in Thailand, with the drone market here expected to reach 500 million baht this year, up from 300 million in 2015.

While not wanting to thwart their use in genuine cases where they can be of benefit to businesses or state agencies, police are nonetheless worried many people do not know they need permission to fly the devices, and are planning a crackdown on unauthorised use.

As it is still a new area, Pol Lt Gen Thitiraj has assigned the Crime Suppression Division (CSC) to study the laws that the police may need to call on when implementing their suppression drive against unauthorised drone flying.

Police are aware of recent incidents of drones being caught while flying over the Grand Palace, some government offices, a military camp and even an airport, he said.

Approval to fly drones is required under a 2015 ministerial announcement by the Transport Ministry. The announcement also lays down rules for drone flyers in cases where permission is granted.

''They are prohibited from flying their drones into or over a hospital, security agencies, flying higher than 300 metres from the ground or violating the rights of others,'' he said.

"The anti-drone device we are thinking of buying will help deal with drones which violate the ministry's regulation," said Pol Lt Gen Thitiraj.

Some anti-drone interceptors overseas fire netting at drones to stop them flying. Others used high-pressure water to bring them back to earth.

The National Broadcasting and Telecommunications Commission has anti-drone equipment of its own.

It uses high radio frequencies to tackle illegally operated drones, as many drone interceptors do. However, police believe the equipment may now be out of date, as technology in this area is evolving rapidly.

During the coming royal cremation, in particular, drone users are being warned they are prohibited from flying their drones in or near the royal cremation site, he said.

This does not include those drones which have been granted permission to be flown at the ceremony to capture aerial views of the cremation.

Pol Maj Gen Suthin Sapphuang, chief of the CSD, said officers are preparing to use up to three laws to curb unauthorised drone flying, a 2015 Aviation Act, a 1954 Act and the Transport Ministry's 2015 announcement.

A violation of the ministry's announcement may also be considered a violation of the aviation law, which can result in a maximum jail sentence of one year and/or a maximum fine of 40,000 baht, he said.

The offence will bring a more serious penalty if the drone is used to carry military hardware, other dangerous items, or animals, he said.

The ministry's announcement says any drone weighing more than 2 kilograms but less than 25kg must be registered with the Transport Ministry and users must be at least 20 years old, he said. The age limit drops to 18 for drones lighter in weight.

A source who is a member of the team looking at the laws to be employed to curb illegal drone flying activities said police began taking the drone matter seriously after reports that some drones had been flown into military camps and other government offices.

Worse still, drones are also seen as an escalating security threat at many airports, especially because most drones are now equipped with cameras.

As for the anti-drone equipment, the source said it will work by detecting the frequency of the illegal drone and shoot it down with a high velocity water gun.

The unwanted drone also will be seized and inspected as police trace its owner who will consequently face legal action for operating a drone without permission.