The Ekstraklasa pacesetters - managed by former Blackburn Rovers boss Henning Berg - were being held 0-0 at home to their mid-table rivals when crowd trouble in the stands at the Pepsi Arena halted the action.
The police were subsequently asked to intervene, before referee Tomasz Wajda called the match off.
At a press conference, Legia safety director Dariusz Derewicz said: "Today (in) the stands (there) were incidents involving spectators.
"As the head of security of the event at about 18:35 (local time) I asked the police for assistance. The police entered and at 18:42 the representative of the city of Warsaw issued a decision…of immediate enforceability of the termination of the event."
Derewicz confirmed that supporters were subsequently asked to leave the stadium.
Legia suggested on their official website that a meeting of league officials will now likely be held on Wednesday, at which a decision will be taken on the outcome of the game.
