Ssl – Validating HTTPS clients with certificates signed by other CAs than server’s CA

I have an apache web server, ssl on that has a server certificate signed by a trusted official CA.
Can I configure apache ssl to accept clients with valid certificates signed by CAs other than the CA that signed the server certificate ?

I'm getting an ssl_error_unknown_ca_alert even though I have configured other CAs in apache and the server started with no errors.
I have created a file containing the CA certificate of the CA that signed the server certificate and the other CAs certificates of the CAs I want to trust. Then I pointed the SSLCertificateChainFile directive to this file.

I'm using Apache 2.2.22

Edit:

I'm using
SSLCertificateFile pointing to server certificate
SSLCertificateKeyFile poiting to server key
SSLCertificateChainFile pointing to the certificate chain that signed the server certificate
SSLCACertificateFile pointing to a file with all the certificate chains I want to be accepted

SSLVerifyClient require
SSLVerifyDepth  1

Apache recognizes them all in the log when I restart server and there's no errors. Yet, I still got a ssl_error_certificate_unknown_alert error.
I also verified that the client certificate chain is present in the SSLCACertificateFile by text comparing in Meld.