Invasion (1965)

Starring Edward Judd, Yoko Tani, Valerie Gearon, Lyndon Brook, Ric Young
Directed by Alan Bridges
(actor & director credits courtesy IMDB.com)

During a late shift at a British hospital, a man struck by a car is brought in whom the doctors soon discover is not human, and learn that there are two other alien beings on the loose.

I really enjoyed this British science fiction picture, which has an intelligent script, builds suspense slowly and admirably, and is well-staged and directed by Bridges.  The filmmakers made the decision to cast Asians as the aliens, which is notable in that the same approach was used the next year in the American film, Women Of The Prehistoric Planet.  Asian actress Tsai Chin, who played Christopher Lee's daughter in Britain's Fu Manchu films, is a human nurse in the film, who points out the aliens aren't Chinese or Japanese.  Judd and Gearon and Brook are fine as the doctors, who aren't perfect and have their flaws, but soon are on a race to save the patients in their hospital from danger that the aliens bring to them.  The film scrimps on special effects for the most part, using clever ideas to keep the budget down and still convey the otherworldliness of the visitors, but closes with a very well designed chase sequence.