A complex type without an element in XSD

Is it possible to define an XSD having only complex types without xs:elements?

Something like:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema version="1.0" xml:lang="en" xmlns:xs="http://ift.tt/tphNwY" elementFormDefault="qualified">
    <xs:complexType name="complexType1">
        <xs:sequence>
            <xs:element name="element1" type="xs:string" minOccurs="1" />
            <xs:element name="element2" type="xs:string" minOccurs="1" />
        </xs:sequence>
    </xs:complexType>
</xs:schema>

Or do we have to include at least a single xs:element of the defined complex type?