BAGHDAD — Hundreds of protesters stormed Baghdad’s heavily fortified Green Zone on Saturday and entered the Parliament building, waving Iraqi flags, snapping photographs, breaking furniture and demanding an end to corruption. The episode deepened a political crisis that has paralyzed Iraq’s government for weeks.

As the chaos unfolded in the afternoon — one lawmaker was attacked, and protesters damaged several vehicles near Parliament — the Baghdad Operations Command announced a state of emergency, deploying additional forces around the capital city. Checkpoints at city entrances were closed, even as the protests remained largely nonviolent.

The scenes of protest, circulated in photos and videos on social media sites, were potent illustrations of the anger that has grown during months of protests by Iraqis demanding that Prime Minister Haider al-Abadi carry out measures to end sectarian quotas in politics and fight corruption.

The protesters were mostly supporters of the powerful Shiite cleric Moktada al-Sadr. Rather than pushing for the ouster of Mr. Abadi, they have largely supported the prime minister as he has sought to make good on promises, still unfulfilled, to improve how the government works.