diff --git a/skiros2_common/src/skiros2_common/core/world_element.py b/skiros2_common/src/skiros2_common/core/world_element.py
index f4a5ac8..59a7a0f 100644
--- a/skiros2_common/src/skiros2_common/core/world_element.py
+++ b/skiros2_common/src/skiros2_common/core/world_element.py
@@ -150,9 +150,13 @@ def getIdNumber(self):
         """
         @brief Return the element id number as integer
         """
-        if self._id.find('-') < 0:
+        hash_pos = self._id.find('#')
+        # Search after # if there is one
+        if hash_pos == -1:
+            hash_pos = 0
+        if self._id.find("-", hash_pos) < 0:
             return -1
-        return int(self._id.split('-')[1])
+        return int((self._id[hash_pos:]).split('-')[1])
 
     def setUri(self, eid):
         self._setLastUpdate()
diff --git a/skiros2_world_model/src/skiros2_world_model/core/ontology_rdflib.py b/skiros2_world_model/src/skiros2_world_model/core/ontology_rdflib.py
index 23879af..9e4d00e 100644
--- a/skiros2_world_model/src/skiros2_world_model/core/ontology_rdflib.py
+++ b/skiros2_world_model/src/skiros2_world_model/core/ontology_rdflib.py
@@ -67,11 +67,11 @@ def lightstring2uri(self, name):
         if name == "":
             return None
         if name.find("#") > 0:
-            return name
+            return rdflib.term.URIRef(name)
         if name.find(":") < 1:
             if name.find(":") == 0:
                 name = name[1:]
-            return self.add_default_prefix(name)
+            return rdflib.term.URIRef(self.add_default_prefix(name))
         tokens = name.split(":")
         for prefix, uri in self._ontology.namespaces():
             if tokens[0] == prefix:
diff --git a/skiros2_world_model/src/skiros2_world_model/core/world_model.py b/skiros2_world_model/src/skiros2_world_model/core/world_model.py
index c92b070..4e4e70a 100644
--- a/skiros2_world_model/src/skiros2_world_model/core/world_model.py
+++ b/skiros2_world_model/src/skiros2_world_model/core/world_model.py
@@ -548,9 +548,10 @@ def _uri2type(self, uri):
         return uri.split('-')[0]
 
     def _uri2id(self, uri):
-        if uri.find('-') < 0:
+        hash_pos = uri.find('#')
+        if hash_pos < 0 or uri.find("-", hash_pos) < 0:
             return -1
-        return int(uri.split('-')[1])
+        return int((uri[hash_pos:]).split('-')[1])
 
     @synchronized
     def load_context(self, filename):