Israeli police spokesman Micky Rosenfeld says that he believes the explosion is criminal but can not definitively rule out a political motive. Local media is quoting an eyewitness who says he saw a motorcyclist throw a package towards the car that exploded.
Assassination by bomb has become a favourite method for Israeli criminal gangs to settle disputes in recent years.
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A report published by the Boundary Commission for England details plans to reduce the number of MPs by scrapping 50 constituencies.
The slump will spark scrutiny, especially as statistics show a rise in racially or religiously motivated offences following the EU vote.
The 53-year-old was killed shortly after leaving her home in Mosta, Prime Minister Joseph Muscat said.