MASKED robbers tied up two female workers at fast-food chain McDonald's and threatened them with a machete during a terrifying raid.

The three balaclava-clad robbers struck as the women were locking up the restaurant, off Bolton Road, near Ewood Park, Blackburn.

They threatened the women with the machete, a knife and a cosh and forced them into the back.

One of the women, 18, was then tied up by her hands and her feet behind the counter.

The robbers forced the other woman, 20, to open the safe, before she too was tied up in the raid.

Police said the incident happened at 12.30am yesterday.

The robbers then escaped with more than £2,000, of which £1,000 was in one pound coins, out of the main entrance into Livesey Branch Road.

Police were quickly alerted as the women had managed to struggle free and dial 999.

Detective Inspector Paul Withers said the ordeal had lasted between five and then minutes.

He added: "Clearly both the victims are extremely traumatised by what's happened.

"The men were violent and aggressive.

"It appears that it has been planned because they were tied up.

"We are very keen to track them down and lock them up."

He said the 18-year-old had suffered minor injuries to her wrists and ankles from the bindings used to tie her up.

He said that any stores or banks should be wary of anyone coming in with a large amount of pound coins.

The restaurant re-opened as normal yesterday, and a company spokesman said it was doing all it could to help the police with their enquiries.

The spokesman added: "We can confirm that an incident took place at our Ewood restaurant.

"We are pleased to say that the staff members present were not hurt, but are being offered support following their experience."

Two of the men were described as being 5ft 10ins tall.

They were both slim and were wearing dark coloured clothing.

The third man was 5ft 8ins tall, also slim and was wearing a dark top and light tracksuit bottoms.

All the men were white and spoke with local accents.