Block sitemap caching

Hi.

I saw in cache stat that sitemap files are cached.

1	svetiksch.spb.ru/sitemap-pt-post-2011-08.xml	svetiksch.spb.ru80/sitemap-pt-post-2011-08.xml	454	X
2	svetiksch.spb.ru/sitemap-pt-post-2011-03.xml	svetiksch.spb.ru80/sitemap-pt-post-2011-03.xml	474	X
3	svetiksch.spb.ru/sitemap-pt-product-2016-10.xml	svetiksch.spb.ru80/sitemap-pt-product-2016-10.xml	479	X
4	svetiksch.spb.ru/sitemap-pt-post-2010-12.xml	svetiksch.spb.ru80/sitemap-pt-post-2010-12.xml
etc.

The cache forbidden list contained default values, including
\sitemap*.xml
I also tried
/sitemap*.xml
and
sitemap*.xml
but still see the above files in cache. How to avoid sitemap caching?