Police are urgently trying to trace a man named as Anthony Lawrence in connection with the incident, with sniffer dogs, helicopters and armed police teams scouring the village of Southburn near Driffield.
Officers had been called to a house last night after reports of a "nasty" attack against a man and a woman, confirming today that the man has since died.
The entire village has been cordoned off as police investigate, with officers stating that a vehicle has now been found.
Neighbours have now spoken of their horror at hearing of the tragedy in this normally peaceful village.
"I've never known a quieter village for something like this to happen in," said Chris King, 25.
"We're still on lockdown here in the village tonight and there are a lot of police, and armed police on foot.
"You have a lot of fields and hiding places in and around the village so the police are going to have a tough time finding him.
"I can see that the police have now gone into the woods and they are searching there."
East Riding councillor for the Southburn area, Coun Felicity Temple said: "It is a terrible shame and I am very sorry it has happened.
"Obviously, my deep heart-felt sympathies go out to the family of those involved."
In a direct plea issued to Mr Lawrence earlier today, Chief Inspector Andy Parsons called on him to come forward.
“Anthony, it’s vital that we speak to you about this incident as soon as possible and I would urge you to go straight to your nearest police station so that we can do this," he said.
“Avoiding speaking to us could only make matters worse for you in the long run.”
Police say the victims' family is being supported by specialist officers. The woman’s injuries are not believed to be life threatening.
And while police have said this is believed to be an isolated incident, they have warned members of the public not to approach Mr Lawrence.
Chief Insp Parsons added: “At this point it is believed that this was an isolated incident and there is no threat to the wider public.
“However, if you believe you have seen Anthony Lawrence or have any information about his whereabouts, please don’t approach him yourself. Call us on 999.”
Mr Lawrence is described as white, 55-years-old, around 5ft 10in tall, balding, with close cropped dark hair and large build, and from the Southburn area.
A Humberside Police spokesperson added: "Our teams - including dog units and the police helicopter - are continuing to work to urgently trace the suspect and establish the circumstances of last night's events."