Karen Gillan has warned fans that the upcoming finale of Doctor Who is emotional.

The actress, who plays Amy Pond, explained that viewers will need "tissues", PA reports.

She refused to reveal too many details about the episode but teased: "I'm going to say the word 'horses' and that's it."

Gillan also admitted that the episode had been one of the hardest to film.

"The second part of the finale was the most difficult because it's a big climax for Amy and her story that's been building through the series," she said. "And it just required a lot of kind of concentration and emotion."

Doctor Who continues on Saturday at 6.40pm on BBC One.