Malawian authorities have charged three ruling party officials with treason for carrying guns to a meeting with President Bingu wa Mutharika.
Malawian officials said the three men - Alfred Mwechumu, Roy Coomsy and Harry Thomson - were first arrested on Monday during a routine security check as they were heading to the meeting in the commercial capital, Blantyre.
The three were later released on bail, but they were re-arrested Wednesday on new charges of treason.
Reuters news agency quotes Malawi's Attorney General Ralph Kassambra as saying authorities had information that "some politicians" had been plotting to kill the president.
Officials said Monday's meeting - planned to seek ways to heal a rift between supporters of President Mutharika and former President Bakili Muluzi - was canceled after the discovery of the weapons.
Some information for this report provided by AFP and Reuters.