Two women were held prisoner in a Blackpool property while it was raided by thieves who stole cash and jewellery.
Police are hunting two men who burst into the property on Banks Street, Blackpool, shortly after 10am today.
Officers said two women were inside at the time of the raid.
A Lancashire Police spokesman said the women - one in her 20s, the other whose age is unknown - were held against their will inside a room in the property by one of the men.
Meanwhile, the other searched the place before the pair made off with their haul.
A witness reported seeing a police presence throughout the day on Banks Street as investigations got underway.
Police were unable to confirm the value of the money and jewellerytaken in the raid or provide a description of the offenders.
The force spokesman said: "Some time between 10am and 10.15am, two offenders have entered a property and then taken some money and some jewellery.
"One of the offenders has come in and kept (the women) secure in one room while the other has come and searched the property."
No arrests have been made so far.
Anyone with information is asked to call police on 101, quoting crime reference WA1715323.