Burma politicians, activists and others shocked by the assassination of a long-time adviser to leader Aung San Suu Kyi gathered at a cemetery for his funeral.
Ko Ni, a prominent member of Burma's Muslim minority, was shot in the head at close range as he walked out of Rangoon airport on Sunday.
The Ministry of Information said in a video posted on state-run MRTV that the gunman was arrested after he wounded a taxi driver who tried to stop him from fleeing.
The ruling National League for Democracy party issued a statement denouncing the assassination and adding authorities are trying hard to track down accomplices of the arrested gunman.
The NLD said Ko Ni was irreplaceable, both to Ms Suu Kyi and the party.