Complex sentence: In addition, on 25 July, the Republicans set fire to the Marconi Station and fired shots at it because they considered the station "a British concern", and because the station had been used by the RIC in their March 1921 call for reinforcements.
Split into simpler sentences: In addition, on 25 July, the Republicans set fire to the Marconi Station and fired shots at it. This was ostensibly because they considered the station "a British concern", and because the station had been used by the RIC in their March 1921 call for reinforcements.