The US Transportation Security Administration (TSA) has an entertaining, if slightly frightening, Instagram feed showing items that were confiscated at airports.

Among the objects seized are a knife disguised as an iPhone cover, an innocent-looking lipstick that turns out to be a taser, and 81 pounds of marijuana.

IBTimesUK presents some of the more unusual items here. Follow the TSA on Instagram for the latest confiscations.

TSA Instagram
This smartphone case was discovered at the Boston International Airport. All knives are prohibited from being carried onto the cabin of an aircraft.TSA Instagram
TSA Instagram
This bear mace was discovered in a carry-on bag at the Anchorage airport. You can pack bear mace in your checked bags if the volume is less than four ounces and it has less than a 2% active ingredient of either CS or CN. Most bear repellents exceed these limitations.TSA Instagram
TSA Instagram
A Mk 2 hand grenade was discovered in a carry-on bag at Los Angeles International Airport. Passengers who bring prohibited items can not only cause delays for others, but also face serious charges. In this case, the checkpoint was closed while an Explosive Ordnance Team transported the grenade to an offsite location to disrupt it. The individual was arrested and is facing felony charges in Los Angeles County.TSA Instagram
TSA Instagram
A taser disguised as a tube of lipstick was discovered in a traveller's carry-on baggage at the St Louis International Airport.TSA Instagram
TSA Instagram
The TSA says: "If it looks suspicious, we take it seriously. Novelty items like this costume watch found at Oakland International Airport can cause alarm at TSA screening lanes and lead to delays. Be mindful of what you pack."TSA Instagram
TSA Instagram
These are just a few of the 150 loaded firearms discovered in carry-on (not checked) bags in June. While they are prohibited as a carry-on, you can pack an unloaded firearm and ammunition in checked baggage in the US as long as it's properly packed and declared. Among other guidelines, the firearm must be placed in a hard-sided locked case.TSA Instagram
TSA Instagram
These comb daggers were discovered in carry-on bags at the Boston Logan International Airport and the Lambert -St Louis International Airport, respectively. All knives are prohibited from carry-on bags, and concealed knives like the ones pictured can result in a civil penalty.TSA Instagram
TSA Instagram
This live stun grenade was discovered in a checked bag at the Memphis International Airport in Tennessee. Needless to say, all live grenades - or anything that resembles a grenade - is prohibited from both checked and carry-on luggage.TSA Instagram
TSA Instagram
This knife disguised to look like an ordinary pen was discovered in a carry-on bag at the Los Angeles International Airport. Artfully concealed items such as this one can lead to fines or even an arrest.TSA Instagram
TSA Instagram
During a routine TSA bag search at Philadelphia International Airport, these narcotics were discovered in a hollowed out book. While TSA staff are not looking for narcotics, they will report them to the proper authorities when they are discovered.TSA Instagram
TSA Instagram
81 pounds of marijuana were discovered in checked baggage at the Oakland International AirportTSA Instagram