Armed raiders held three people hostage in a house before escaping with cash, credit cards and mobile phones.
The attack in Lower Meadow, Harlow, happened late on Saturday evening when two youths in their late teens or early 20s burst into the house, police said.
The raider armed with a handgun is described as of mixed race, medium build, 5ft 10in tall and wearing black padded jacket and jogging bottoms.
The other attacker was described as skinny and also dressed in black.
Both raiders had their faces covered.
The occupants of the house were left shaken and concerned over the reasons they had been "singled out for the crime".
They were herded into a room and locked in while the raiders made their escape.