Does libxml2 support multiple schemas?

As I know:

libxml2 supports schema validation in version 2.6.19.
It uses xmlSchemaParserCtxtPtr->URL to specify URL of .xsd file to validate doc node.
and stored the parsed schema in xmlSchemaParserCtxtPtr->schema

But in my cases, I want to use libxml2 to validate SOAP messages
against several schemas, such as soap2002.xsd，soap12.xsd，xenc-schema.xsd，
and schema specified by Web Services itself.

Does it possible to validate such kinds of SOAP messages using libxml2?

Any suggestions are appreciated.

BR.
Gloria