(Reuters) -Myanmar's junta said it has extended a temporary ceasefire to June to support reconstruction and relief efforts following a massive earthquake in late March that killed at least 3,700 people and devastated parts of the country. The junta initially announced a ceasefire in early April, days after the March 28 earthquake, to support relief efforts, following similar moves by anti-junta armed groups. The opposition groups have also extended their ceasefire to end-June. Military airstrikes and artillery attacks have continued in some parts of Myanmar despite the ceasefire announcement. (Reporting by Reuters staff; Writing by John Mair; Editing by David Stanway)