Police are appealing for information after money and jewellery were stolen from a house in Croxley Green.
At about 1pm on Tuesday three men smashed a panel to the back door of a house in Berkeley Court.
The alarm went off but the offenders continued inside and left along Berkeley Court and into Mayfare with money and jewellery.
Hertfordshire Constabulary searched for the men on foot and used the helicopter.
The suspects are described as three men who were between 5ft 6ins and 5ft 8ins tall who were aged in their early to mid-30s and of a medium build. They were all wearing dark grey baseball caps with red piping along the base and grey bomber jackets.
Assistant Investigator Kevin Deudon said: "I believe that the offenders will have left a vehicle in a road nearby, perhaps in Mayfare or Sycamore Approach. I would appeal to anyone who was in the area and saw three men fitting the descriptions above getting into a vehicle in the area early that afternoon to contact me."
Anyone with information is asked to contact AI Deudon via the Herts Police non-emergency number 101 quoting crime reference number C2/14/1296. Alternatively call Crimestoppers anonymously on 0800 555 111.