Lebanon's caretaker prime minister, Hassan Diab, has declined to be questioned by a judge who charged him and three former ministers with negligence over the Beirut port blast, an official source said on Monday.
The charges brought by Judge Fadi Sawan last week drew strong criticism from influential parties including the Shi'ite group Hezbollah and Sunni leader Saad al-Hariri.
Some politicians have suggested that Sawan was selective in deciding who to charge, and that he overstepped his powers by charging government ministers. Others have said he showed courage.