diff --git a/05-osm-usage.md b/05-osm-usage.md
index c2f48cb9a945992d6fd765f325c3be71f99835d8..a89db42aaf1e3bf1c1373b064a9421c99b0bea33 100644
--- a/05-osm-usage.md
+++ b/05-osm-usage.md
@@ -2009,6 +2009,21 @@ __Step 2: See the notification in notification receiver.__
 - Support for subscription and notification for VNFD.
 - Cache to store subscribers.
 
+## How to cancel an ongoing operation over a NS
+
+The OSM client command `ns-op-cancel` allows to cancel any ongoing operation of Network Service. For instance, to cancel the instantiation of a NS execute the following steps:
+
+1. Create the NS with `osm ns-create` and save the Network Service ID (NS_ID)
+2. Obtain the Operation ID of the NS instantiation with `osm ns-op-list NS_ID`
+3. Cancel the operation with `osm ns-op-cancel OP_ID`
+4. The NS will be in `FAILED_TEMP` status.
+
+Be aware that resources created before the cancellation will not be rolled back and the Network Service could be unhealthy.
+
+If some operation is blocked due to an ungraceful restart of LCM module, you can use this command to delete the operation and unblock the Network Service.
+
+Queued (unstarted) operations can also be deleted with this command. 
+
 ## Start, Stop and Rebuild operations over a VDU of a running VNF instance
 
 These three operations involves starting , stopping, and rebuilding of a VDU on a running VNF instance by using the NGUI. 
diff --git a/10-osm-client-commands-reference.md b/10-osm-client-commands-reference.md
index b2f13ef6e5bdb8dc7c155100bbf850d595f049b5..ce8f40a7eac747619890e3127976d86fbd54c3d5 100644
--- a/10-osm-client-commands-reference.md
+++ b/10-osm-client-commands-reference.md
@@ -53,6 +53,7 @@ Commands:
   ns-delete                  deletes a NS instance
   ns-list                    list all NS instances
   ns-metric-export           exports a metric to the internal OSM bus, which can be read by other apps
+  ns-op-cancel               cancels an ongoing NS operation
   ns-op-list                 shows the history of operations over a NS instance
   ns-op-show                 shows the info of a NS operation
   ns-show                    shows the info of a NS instance
diff --git a/12-osm-nbi.md b/12-osm-nbi.md
index 090a37c4e1c51990892989e58a845493efa3802d..5d9642431f9be17be3cc0012e1f3b1b14068b293 100644
--- a/12-osm-nbi.md
+++ b/12-osm-nbi.md
@@ -118,7 +118,7 @@ URL: /osm                                                       GET     POST
                     heal                                                5
             /ns_lcm_op_occs                                     5       5
                 /<nsLcmOpOccId>                                 5                       5       5
-                    TO BE COMPLETED                             5               5
+                    cancel                                              05
             /vnf_instances  (also vnfrs for compatibility)      O
                 /<vnfInstanceId>                                O
             /subscriptions                                      5       5