State media reports in Burma say the government has named the military's fifth-ranked general, Thein Sein, as acting prime minister.
The reference was made in an article by the state-run "New Light of Myanmar" newspaper.
Foreign news reports say the incumbent prime minister, Soe Win, is in Singapore for cancer treatment.
However, Burma's military government has denied that Soe Win is ill.
Information for this report is provided by AP and AFP.