BAGHDAD, Iraq -- Bloodshed surged in the capital Saturday, with at least 17 people dead in attacks and 27 probable victims of sectarian killings found dumped in the streets as Iraq's prime minister appealed for reconciliation.

Violence has escalated sharply over the past week. Saturday's toll raised the city's violent deaths to more than 180 since Wednesday -- either slain by bombs and gunfire or tortured and shot before being dumped, a hallmark of reprisal killings between Shiite and Sunni Muslims.

Appealing to Iraq's divided sects, Shiite Prime Minister Nouri al-Maliki urged Iraqis to put aside their sectarian, ethnic and political differences and embrace his reconciliation plan.

"National reconciliation is a correct way of thinking and carries a high feeling of responsibility," he said. "To succeed in this today, we have to embrace the culture of dialogue and reconciliation."

Al-Maliki's plan is intended to bridge the communal animosities fueling Iraq's violence. It offers amnesty to members of the Sunni Arab-led insurgency not involved in terrorist activities and calls for disarming primarily Shiite sectarian militias.

But no major Sunni insurgent group has agreed to join the plan, and no steps have been taken to rein in Shiite militias. Since the plan was unveiled in late June, car bombings, mortar attacks and shootings have killed hundreds.

Al-Maliki said that once the plan created an "atmosphere of reconciliation and dialogue," his government would take steps based on the views expressed both by non-governmental groups and by tribal leaders -- who last month agreed to back his effort.

The U.S. military confirmed that Iraqi forces plan to dig trenches and set up berms around Baghdad in an attempt to prevent insurgents and explosive-laden cars from getting into Baghdad.

"There is a plan in progress for a security belt around Baghdad that includes trenches and other obstacles for channeling exit from and entry to the city through checkpoints controlled by Iraqi forces. This is a cooperative effort between the Iraqi government and the coalition," said Lt. Col. Barry Johnson, a military spokesman.