SPARQL-query to get data from wikidata not working - sparql

Question

I try to get some image links from wikidata by running a SPARQL-query from my local Jena Fuseki instance. I want to merge it with data from my local graph. Unfortunately the query isn't delivering any data but runs and runs instead without any error message.
The sparql-query:
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT ?name ?image WHERE {
?s foaf:name ?name.
?s owl:sameAs ?wikidata_link.
FILTER regex(str(?wikidata_link), "wikidata").
SERVICE <https://query.wikidata.org/sparql> {
?wikidata_link wdt:P18 ?image.
}
} LIMIT 10
The test data I have in my local graph on the Jena Fuseki server:
#base <http://dmt.de/pages> .
#prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
#prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
#prefix foaf: <http://xmlns.com/foaf/0.1/> .
#prefix dbp: <http://dbpedia.org/resource/> .
#prefix wd: <https://www.wikidata.org/entity/> .
#prefix owl: <http://www.w3.org/2002/07/owl#> .
<#john-cage>
a foaf:Person ;
foaf:name "John Cage";
owl:sameAs dbp:John_Cage, wd:Q180727.
<#karlheinz-stockhausen>
a foaf:Person ;
foaf:name "Karlheinz Stockhausen";
owl:sameAs dbp:Karlheinz_Stockhausen, wd:Q154556.
<#arnold-schoenberg>
a foaf:Person;
foaf:name "Arnold Schönberg";
owl:sameAs dbp:Arnold_Schoenberg, wd:Q154770.
I tried a similar query for dbpedia-data which run perfectly.
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX dbp: <http://dbpedia.org/resource/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX dbo: <http://dbpedia.org/ontology/>
SELECT ?name ?dbpedia_link ?birthplace WHERE {
?s foaf:name ?name.
?s owl:sameAs ?dbpedia_link.
FILTER regex(str(?dbpedia_link),"dbpedia.org").
SERVICE <https://dbpedia.org/sparql> {
?dbpedia_link dbo:birthPlace ?birthplace.
}
} LIMIT 10
Any Ideas? Thanks in advance!