Peel cucumbers and halve lengthwise.
Scoop out seeds with spoon and discard.
Cut cucumbers into chunks.
Place cucumbers, onion and garlic in food processor.
Process until smooth.
Add 1 cup yogurt and process until smooth.
Scrape into a medium bowl or soup tureen.
Stir in remaining 1 cup yogurt, mint, salt, pepper and ground red pepper.
Cover; chill at least 2 hours before serving.