A sonic boom heard by people around Stamford and Bourne was caused by military jets flying to intercept a civilian plane.
Reports of the noise came from Market Deeping, Tallington, West Deeping and Bourne and could be heard as far away as Peterborough and Huntingdon.
Many people said their homes were shaken by the boom which was heard just after 1pm.
A spokesman for RAF Coningsby said: “The Ministry of Defence can confirm that Typhoon aircraft from RAF Coningsby were launched from quick reaction alert this afternoon to investigate a civilian aircraft which had lost radio contact with air traffic control.
“The civilian aircraft re-established communication prior to intercept and was released to proceed en route. The Typhoon aircraft were authorised to go supersonic over land for operational reasons, any inconvenience caused to local residents is regretted.”
Tallington resident Ken Otter said people had rushed into the streets to see what had happened. He added: “People came out because everything shook. You could hear a jet in the distance going away.
“I’ve never heard it like this before. It just felt as if there was a huge explosion.”
Plenty of people reported hearing the noise on Twitter, with many using the #sonicboom hashtag.
User @glamglyn said: “thought it was a bomb in Market Deeping. Whole house shook. Rushed out and heard the plane #sonicboom.”
@JanetKonik said: “It shook our house. Realised what it was but still scary!”
And @adamwarrington said: “heard it in Market Deeping, thought something had crashed into the roof.”