Police used smoke canisters and tear gas overnight following reports of a shooting minutes into a curfew imposed in violence-torn Ferguson, Mo.

Crowds defied the five-hour curfew, but officials stressed that officers clamped down in response to the shooting, not protests.

“Officers approached the barbecue and deployed tear gas to … get to the shooting victim,” Missouri Highway Patrol Captain Ron Johnson told reporters.

“A police car at location was shot at,” he added.

Seven people were arrested, according to reports, but the shooter remains at large. The male victim of the shooting is in critical condition.

Missouri Gov. Jay Nixon (D) declared a state of emergency on Saturday, following a week of protests after a white police officer shot and killed an unarmed black teenager, Michael Brown.

Nixon said he imposed the curfew to "maintain peace.”

"We will not allow a handful of looters to endanger the rest of this community,” Nixon said at a news conference in Ferguson. “If we're going to achieve justice, we must first have and maintain peace.”

Earlier in the week, Nixon replaced the St. Louis County police with the Missouri Highway Patrol after criticism of the local force’s tactics.