Iraqi security forces on Thursday began the second phase of their offensive against Islamic State militants in Mosul, pushing from three directions into eastern districts where the battle has been deadlocked for nearly a month.

Since the offensive to capture Mosul began 10 weeks ago, U.S.-backed forces have retaken a quarter of the jihadists’ last major stronghold in Iraq in the biggest ground operation there since the 2003 U.S.-led invasion that toppled Saddam Hussein.

More than 5,000 soldiers and federal police troops, redeployed from Mosul’s southern outskirts, entered half a dozen southeastern districts, while counter-terrorism forces advanced in al-Quds and Karama districts after reinforcements arrived. […]