urgent problem with SEPM and the group command "Update Content"

Hi all, we have urgent problem with SEPM.

In a center, by mistake, has launched a group command "Update Content" to all computers and network is saturated.

We had to shut down the server and network SEPM has recovered.

We need to know in what way you can stop remaining commands because there is still 50% and will re-saturate the network.

I await your urgent response

thank