Small bird in reed bed

Hi all, on a quick visit to Radipole on Sunday 14th, I noticed a small brown bird rummaging around in a reed bed. It would then perch on a reed to quickly fly up to catch ( I think) an insect. I didn't have any means to see it closer. It was about 10ms away. I thought it might be a Cetti's Warbler but....Can anyone give me any clues as to what it might have been or confirm my original assumption?
Neilo