BAGHDAD (AP) — Sunni militants have blitzed through the vast desert of western Iraq, capturing four towns and three border crossings and deepening the predicament of the Shiite-led government of Prime Minister Nouri al-Maliki.

Their latest victories — including two border posts captured Sunday, one along the frontier with Jordan and the other with Syria — considerably expanded territory under the militants’ control just two weeks after the al-Qaida breakaway group started swallowing up chunks of northern Iraq, heightening pressure on al-Maliki to step aside.