I have noticed that my units tend to lose men while they are besieged in city. This I dont understand. I can only see two reasons for losing men in the garrison during a siege.

1. the besiegers and garrison shoots at eachothers during the siege.

But this seems very unlikely because I dont think there would be any fighting before the assault, plus I havent seen any besiegers taking casulties during a siege.

2. the garrison dies from starvation.

This seems very inlikely too, because I dont understand why people would began to die after the first turn when the grain storage is supposed to last for 9 turns.

So why am I losing men when I am besieged????