berlin reason suspect two bag bullets find near christmas market mosque western berlin anything terrorism find relate neither market mosque police say sunday ask possible link terrorism police spokesman say ammunition always find berlin add somebody probably clear cellar find something grandfather germany high alert militant attack nearly year tunisian islamist ram hijack truck christmas market central berlin kill 11 people well driver early month experts make safe device fill nail deliver pharmacy near christmas market german city potsdam near berlin berlin police say bag bullets find near christmas market link terrorism