BAGHDAD — More than 1,700 people were killed in Iraq in July, the United Nations said Friday, making it one of the deadliest months of the year but marking a decline from the previous month, when Sunni militants swept across much of the country.

The U.N. mission to Iraq said in its monthly statement at least 1,737 people were killed in July, down from 2,400 deaths in June, when the Islamic State group spearheaded a lightning blitz that saw Sunni militants seize much of northern and western Iraq.

But the latest figure is considerably higher than May, when some 800 people were killed, and the latest toll includes an increase in killings in areas now under the control of militants.

Iraq’s U.S.-trained and equipped military melted away in the initial militant onslaught, but has since regrouped, and the battle lines largely stabilized last month as the Sunni militants approached Shiite-majority areas.

Calls for Prime Minister Nouri al-Maliki to resign have intensified since the crisis began, with critics accusing him of monopolizing power and alienating minority groups.

The Shiite leader has vowed to serve a third four-year term, however, as lawmakers have struggled to agree on a new government that can confront the crisis. Al-Maliki’s bloc won the most votes in April’s parliamentary elections.

The U.N. mission again called on the country’s feuding politicians to set aside their differences and form an inclusive government.