An armed gang tied up a family in their home in South Lanarkshire before stealing jewellery worth more than £100,000.
Four men forced their way into the house in Blantyre Road, Bothwell, at about 19:30 on Tuesday.
The father, 59, and mother, 56, were threatened with weapons including a knife before being tied up.
Their 11-year-old son was also bound before they raided the property.
Police said jewellery and watches worth a six-figure sum were taken from the home.
The family were uninjured but left "extremely" shaken.
The suspects all spoke in what is described as broken English.
Det Insp Susie Cairns said: "This was a very traumatic experience for this family and I would like to reassure the public that we are doing everything possible to track down the four men responsible.
"Officers are currently carrying out enquiries into this robbery and gathering CCTV footage to gather more information on the four men responsible.
"There are also additional police patrols in the area to provide public reassurance.
"We do, however, need the help of the local community and at this time we are urging anyone who may have seen these men in the area prior to the robbery taking place, or who may have seen them leaving afterwards, to contact police immediately."
All the suspects are said to be about 5ft 10in tall.
The first is said to be stocky with an olive complexion, wearing dark-coloured clothing including a jacket, scarf, hat, tracksuit trousers and black boots. He was carrying a black-and-white rucksack.
The second was of medium build with an olive complexion. He was also wearing dark-coloured clothing including a hooded jacket, tracksuit trousers, hat and woollen gloves. He wore black, beige and green camouflage print Adidas trainers.
The third was of medium build with fair complexion. He was wearing a dark-coloured hooded top with a scarf covering the lower part of his face. He also had gloves, navy tracksuit trousers and black Nike trainers.
The fourth was of medium build with a fair complexion, wearing a dark-coloured thin padded jacket with stitched squares. He was wearing dark brown trainers with no socks.