Maltese Prime Minister Joseph Muscat announced eight of the arrests at a press conference this morning, when he said the detainees are being questioned on "reasonable suspicion" of involvement in the 16 October auto bombing of Caruana Galizia, the Times of Malta reports.
"I have been informed of a security operation that took place this morning", Muscat said, adding he believed it was in the best national interest to inform the public about the operation.
Addressing an urgent press conference in Castille, Muscat refused to provide details on the arrests, including on whether the people are suspected to be the executors or the masterminds, arguing such details risk prejudicing the investigations.
The head of the Parliament's delegation, socialist lawmaker Ana Gomes, said the murder "was aimed at instilling fear in everyone, especially those involved in investigating and prosecuting cases of money laundering and corruption".
Political blogger Daphne Caruana Galizia was killed when her auto was blown up.
She was killed as she was driving near the village of Bidnija in northern Malta.
"As I stated as soon as I learnt about this barbaric act, we will leave no stone unturned to get this case solved", he said.
Her murder raised concern within the European Union about the rule of law in Malta, and many saw it as an attack on independent media.
Recently, Caruana Galizia's outspoken blog had turned its fire on opposition politicians. "The situation is desperate", she wrote minutes before she died in a blast so powerful her vehicle was blown to pieces and her body was catapulted into a nearby field.
'There are crooks everywhere you look now. She leaves a husband and three sons.