ARMED robbers struck twice in Kirklees, just two hours apart.
Detectives are probing possible links between the crimes in Dewsbury and Cleckheaton on Thursday.
In both cases the victims were threatened with knives and a gun.
The first happened at Laith Hall Avenue in Cleckheaton at 4.50pm, when three masked men carrying a machete and a gun went in and demanded money. They fled empty-handed.
Just two hours later three masked men, again armed with a large knife and a gun, demanded cash from people at a house on Chadwick Crescent in Westborough, Dewsbury. Police are not sure if anything was stolen, but the men again escaped on foot.
Det Insp Bob Davies from Dewsbury CID said: "Police are not linking the incidents at this stage, but also not discounting the possibility they may be connected.
"Although no-one was seriously injured in the incidents, they are serious matters.
"I would ask that if anybody saw the offenders before they went in or out of either house, or any vehicles they were using, to pass that information to Dewsbury CID.’’
Contact detectives on 01924 4310859 or phone Crimestoppers on 0800 555 111.