Unknown nginx log error

Hi

Today i got this error on nginx log and nginx restart at this time but i don't know why:

[code]
03:06:01 [alert] 30292#0: unlink() "/usr/local/nginx/logs/nginx.pid" failed (2: No such file or directory)
[/code]

At this time nothing else run like a cron or anything that be able to do that :(

Any ideas?

Thanks