Simplify the following text for a Grade 13 native English-speaking person.
Original: The demonstration was to demand the release of two popular leaders of the Indian Independence Movement , Satya Pal and Saifuddin Kitchlew , who had been earlier arrested by the government and removed to a secret location .
Simplified: The demonstration was held to demand the release of two popular leaders of the Indian Independence Movement , Satya Pal and Saifuddin Kitchlew , who had been earlier arrested on account of their protests .