Two shop assistants were brutally forced to the floor and locked in a store room while robbers made off with a large amount of cash.
The two women, who are both in their 50s but do not want to be named, were working at off licence The Local, in Field End Road, South Ruislip, on Saturday, when two men came into the shop at about 8.20pm.
One assistant said: "I was coming out of the back office when I saw one man. I was about to tell my colleague that I thought he looked suspicious when he grabbed hold of me and pushed me into the back office, where I was brutally forced to the floor.
"Everything went black for a moment and he kept telling me to open the safe.
"I had to tell him it was on a 10-minute safety lock and he kept saying to me: 'Are you lying?, you best be telling me the truth'.
"Waiting those 10 minutes felt like a lifetime, and I had no idea what was happening to my friend, and what the other masked man was doing to her.
"I have never been more terrified - I didn't know if he was armed or if he was going to rape or kill me or my friend.
"He kept apologising for hurting me and said he was desperate for the money, and I kept thinking: 'What if this was happening to your mother or partner?'
"My friend, who was behind the counter, was forced to her knees and made to crawl along the floor to the back office with me.
"Once they got all the money from the safe, tills and money box, they locked us into the office before running out of the shop with the keys.
"A lady came in and heard us screaming and called the police. We were so grateful to be alive."
One of the suspects is black, about 5ft 4ins tall, with a West Indian accent and was wearing a dark black balaclava with a netted part across the face.
The other is white, about 5ft 8ins, in a dark hooded top with the hood up, and a goatee beard. There was potentially a third suspect in a car outside.
Around £1,300 is thought to have been taken. The owners of the shop refused to comment.
Anyone with information should call PC Jonathan Williams on 020 8246 1568.