Police fire tear gas at Nigeria's legislators, who scale parliament fence after a lock-out

ABUJA, Nigeria – Nigeria's Senate president has suspended legislative proceedings in the National Assembly until Tuesday following a lockout of members by the police.

Senate President David Mark announced the lockout after police fired tear gas to prevent the House of Representatives from convening. Members of parliament resorted to scaling parliament's gate to get inside.

Despite the tear gas, some lawmakers forced their way inside. Some opposition lawmakers shouted that President Goodluck Jonathan must be impeached.

The speaker of the House recently changed allegiance from the president's party to the main opposition party. Afterward the police withdrew his security clearance, triggering Thursday's standoff.

Thursday's parliament session had been convened to discuss Jonathan's request to extend the state of emergency in the country's northeast, where the armed group Boko Haram operates.