Iraqi Prime Minister Nouri al-Maliki has asked for U.S. troops to stop building a wall around a Sunni enclave in a mainly Shi'ite area of Baghdad.

Mr. Maliki told reporters Sunday in Cairo that there are other ways to protect the Azamiyah neighborhood and maintained that sectarian violence in Iraq is largely under control. But U.S. military officials say the concrete wall is needed to end a cycle of Shi'ites-Sunni violence.

In violence around Baghdad Sunday, two suicide car bombers killed 12 people near a police station while the U.S. military says an airstrike killed 15 al-Qaida-linked militants south of Baghdad.

In the north, Iraqi police say gunmen killed 23 members of the Yazidi Kurd religious minority as they traveled home by bus from work.

General David Petraeus, the top U.S. commander in Iraq, told The Washington Post newspaper the increase in American and Iraqi troops since February has improved security in Baghdad and Anbar province. But he said attacks have risen sharply in other regions.