Unable to delete cache – files owned by apache

I’ve just moved my installation to a new subdomain and I’ve been trying to delete the old files but I am not allowed to delete all the wp-content/cache files as they are owned by ‘apache’. I am not apache so cannot do anything with them. I can’t work out why they would have been created with this owner – does anyone have any ideas, and how I might be able to delete them?

Thanks.