VALLETTA, Malta — The killing of an investigative journalist in Malta has stirred an outcry about corruption and criminality on the island nation, raised concerns about freedom of expression and the rule of law and drawn the attention of Pope Francis.

The journalist, Daphne Caruana Galizia, 53, died on Monday when the car she was driving exploded. She had spent years exposing corruption and nepotism among the Maltese elite, and made many enemies.

The killing was condemned by leaders of the European Union — which Malta joined in 2004 — and by the pope, who in a rare message expressing condolences about a private citizen asked the archbishop of Malta to “convey his condolences to her family,” according to a statement that was released on Friday.

The Roman Catholic Church has traditionally been hostile to Malta’s Labour Party, which has been running the country since 2013 and recently infuriated the church by legalizing same-sex marriage.