Up to at least 26 Americans have been caught at UK airports with suitcases full of weed.

The strange phenomenon was brought to light by Vice and the British media who reported Monday that another two Americans were arrested last month at Heathrow – one with nearly 55 pounds of weed and the other with 60 pounds.

Both men were sentenced and will serve 8 months and 10 months in prison.

The National Crime Agency (NCA) Heathrow Branch Commander Andy Noyes spoke on the sudden rise in US-based weed smugglers in a press release on Monday:

“Couriers are often recruited with promises of payment or free holidays. But in reality, these attempts just end in jail sentences,” said Noyes.

“I’d urge anyone considering smuggling cannabis into the UK, whether from the US or elsewhere, to think twice. It isn’t worth the risk,” Noyes continued.

“The NCA and our partners in Border Force are targeting drugs smugglers and will do all we can to disrupt the gangs involved.”

Arriving from states where weed is legal their plan according to the NCA is to sell the high-quality California cannabis for ten times more in the UK.

NCA could not comment on whether it was the work of a single gang, but is investigating whether the attempted imports are linked.

“We are working to understand how these seizures are connected, however, to get this many off the same route in such a short period of time is clearly very unusual,” said the NCA’s senior investigating officer Darren Barr.