Police in Malta have arrested 10 Maltese nationals in connection with the car bomb murder of investigative journalist Daphne Caruana Galizia.
Prime Minister Joseph Muscat told reporters that police operations were under way in the town of Marsa, and the Bugibba and Zebbug areas.
Caruana Galizia was killed close to her home on 16 October in an attack which shocked the country.
The 53-year-old was known for her blog accusing top politicians of corruption.
Early last year she reported that New Zealand trusts set up by Malta Energy Minister Karl Mizzi and Mr Muscat's chief of staff, Keith Schembri, controlled companies in Panama.
The government offered a €1m reward for information about her murder.
International experts, including from the FBI, were called in to help in the investigation.
Police and troops are being used in the security operation, with roads blocked and a patrol boat deployed.
Mr Muscat said some of the detainees were already known to the police while others had criminal records.
When asked if the eight arrested had participated in the murder, or if they also included the mastermind, Mr Muscat would not comment, Malta Today reports.
"I have a clear idea of what they did and who they are but I cannot give out more details at this time," he said.
On her Running Commentary blog, Caruana Galizia had relentlessly reported on alleged corruption among politicians across party lines.
With a career spanning more than three decades, she was "one of Malta's most important, visible, fearless journalists", in the words of former Home Affairs Minister Louis Galea.
Her funeral was attended by hundreds of people but the tiny EU state's leaders were barred by her family.
Her three sons refused to endorse the reward and called on Mr Muscat to resign for failing to uphold "fundamental freedom".
The editors of eight of the world's largest news organisations, including the BBC, called for the European Commission - the EU executive - to investigate the murder.
In response, Frans Timmermans, vice-president of the commission, urged the authorities to leave "no stone unturned" in the case.