Eclipse : Issue with WAR project referencing EAR Project library

I have war project which is included in EAR project, the EAR project has jar files in APP_INF/lib folder.
In java build path under libraries the jar files from EAR project are referenced under Enterprise Application libraries.
i have deleted a jar file in this folder . Once I deleted the jar , i am getting issue in war project as below:

the project references  to non existing library in 
[EAR-PROJECT]/EarContent/APP-INF/lib folder.

I tried to delete the reference of this jar file in Java Build Path –> Libraries–> Enterprise Application Libraries. But I am not able to delete. How do I delete it?