Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/osgi]

Unable to locate Spring NamespaceHandler for XML schema namespace
[http://www.springframework.org/schema/osgi]

I have following exception during Spring initialization:
Caused by:
org.springframework.beans.factory.parsing.BeanDefinitionParsingException:
Configuration problem: Unable to locate Spring NamespaceHandler for XML
schema namespace [http://www.springframework.org/schema/osgi]
Offending resource: OSGi
resource[bundleentry://104.fwk32582392/META-INF/varaza/extender/extender-context.xml|bnd.id=103|bnd.sym=com.pearlox.varaza]
How can I determine which JAR (which Maven artifact contains definition of
proper NamespaceHandler for [http://www.springframework.org/schema/osgi] ?
What my strategy of fixing this should look like?
What else have I to include into my question to help you understand the
situation? (please comment)
P.S.: I see lots of similar questions here on StackOverflow related to
other libraries but answer depends on particular namespace.