Help identifying birds of prey Norwich

Hi

The other day I had two birds of prey flying over my house which is unusual as I live in a suburb of Norwich, Norfolk. 
They had brown and white stripes underneath but due to their call I cannot identify them. They were making a clicking sound. 
There are a lot of large trees in my area, and I am close to an airport and then open fields. 
I once had a Sparrowhawk kill and eat a pigeon in my garden and we do have Peregrine Falcons at the cathedral in the city. 
Any help would be much appreciated!

Thanks in advance!