Between the end of July and this week householders up and down the length of the valley, from Todmorden to Mytholmroyd, have described seeing silently moving bright yellow or orange lights make their way across the sky in a way that does not seem like conventional aircraft.

And another possible explanation, that they are hot air balloons, seems unlikely because the lights are seen in the night sky.

First residents in the Burnley Road area of Todmorden saw patterns of lights on the night of Saturday, July 26.

Gemma Kipping said family guests were visiting. "Some of them left before the others and were walking home but rang us after they had set off to say 'there are aliens above your house!'

"So we went outside and I saw three bright orange lights moving uniformly with what looked like a straggler at the end. The three at the front looked like a triangle effect. They weren't making any noise," she said.

While the family watched, a dozen or so customers from the nearby Hare and Hounds pub on Burnley Road, Todmorden, were also watching the lights move across the sky, said Gemma.

"I didn't know what they were," she added. "The ideal explanation would have been that they were a hot air balloon, but surely not in the dark?"

Similar lights were also seen on the night of Saturday, August 2, at 11.15 pm by other Burnley Road residents including Sylvia Sinclair, who contacted the newspaper after reading about similar descriptions of lights in the sky from residents of Mytholmroyd in our sister paper the Evening Courier.

Sylvia explained that friends were leaving her home at Lineholme when they all saw the lights, which appeared to be coming over to the Whirlaw side of the valley.

"They came in twos and looked like big orange lights. They were making no noise and there were six, in pairs. The last one seemed to float over," she said.

Like Gemma, Sylvia wondered if they could be balloons but thought they were too high for that.

"While we were looking a teenager came down the street and said they were out at the Hare and Hounds looking at the lights. They were just silent, going slowly across the sky," she said.

The next sighting of strange lights came further down the valley, on Monday, August 11, in the Mytholmroyd area.

Cragg Vale resident Chris Granger told the Courier he was shocked to see six strange lights for two to three minutes before they disappeared, emerging from the cloud base in pairs and moving towards Hebden Bridge.

The ex-RAF avionics technician said: "They moved in a very erratic manner and did not display the flight characteristics of a conventional aircraft. Nor did they display the normal lighting array of a conventional aircraft - flashing white strobe and red and green navigation lights."

Cleveley Gardens residents Peter and Marion Ackroyd also saw something spooky.