* Daphne Caruana Galizia killed on Monday as left home
* Government gives first details of investigation
* Sons demand PM quits; he refuses and heads to EU summit
By Crispian Balmer
VALLETTA, Oct 19 (Reuters) - Police believe a bomb that killed a prominent journalist in Malta was attached beneath her car and triggered remotely, a government spokeswoman said on Thursday, giving first details of the investigation.
Daphne Caruana Galizia, a renown blogger and fierce critic of the government, died on Monday in a blast that wrecked her car as she was leaving her house, throwing debris and body parts into a nearby field.
The murder shocked the Mediterranean island, the smallest nation in the European Union, and Prime Minister Joseph Muscat on Wednesday promised a reward to anyone who came forward with information about the killing.
However, Caruana Galizia’s three grown-up sons dismissed the offer, and called instead for Muscat to resign, saying he should take political responsibility for the first such murder of a journalist in Malta since the island won independence in 1964.
Muscat has ruled out quitting and flew to Brussels on Thursday for an EU summit.
His spokeswoman told reporters that British police had joined Dutch forensic experts and a team from the U.S. Federal Bureau of Investigation (FBI) to help with the case.
“Emerging evidences make us think that the bomb was placed under the car and was set off with a remote trigger,” the spokeswoman said.
She said foreign experts should be able to help identify the mobile phone which was used to detonate the bomb.
A local police source said investigators believed powerful Semtex explosives might have been used in the killing, adding that if proven, it would be a first for Malta.
The island has seen a number of small bomb attacks in recent years tied to gangland criminals, but the explosives used were relatively rudimentary and did not have the same power as the device that targeted Caruana Galizia.
The 53-year-old journalist used her widely read blog to lambast Muscat, his wife and some of his closest advisers, accusing them of setting up off-shore accounts to hide ill-gotten gain.
They denied the charges and Muscat was suing Caruana Galizia for libel at the time of her death.
“The police may or may not find out who ordered the assassination of our mother but as long as those who led the country to this point remain in place, none of it will matter,” her three sons, Matthew, Andrew and Paul, wrote on Facebook.
That added that the only way forward was for Muscat to stand aside: “Resign for watching over the birth of a society dominated by fear, mistrust, crime and corruption.”
As he arrived at the EU summit in Brussels, Muscat denied that he had created a “mafia state”.
“Definitely not,” he said. (Additional reporting by Francesco Guarascio in Brussels; Editing by Alison Williams)