无法从SQL Server CE删除记录

I have an ASP.NET MVC application. I use EF 5.0 to persist data in the database of a SQL Server CE type. I have installed SqlServerCe.Enitity NuGet package. I can successfully process Create, Read and Update operations on the database records using Linq and my model object. For some reasons however, I cannot delete any records from the database. Objects are being erased on the model level but changes are not being persisted in the database. What might be causing that?I have an ASP.NET MVC application. I use EF 5.0