Baghdad ? U.S. and Iraqi forces blocked access to a town on the northeast outskirts of Baghdad where Shiite gunmen were dug in for a third day Monday behind earthen barriers. Police issued calls for residents to leave the town, and some said they were running out of food and fuel.

The blockade of Husseiniyah came as at least 16 people died when four car bombs rocked the center of the capital. Three of the blasts took place in one 30-minute span, as the relentless Baghdad summer sun pushed temperatures to 115 degrees.

Police, morgue and hospital officials reported a total of at least 59 people killed or found dead nationwide, and the American military announced the deaths of three soldiers and a Marine.

The continued fighting and deaths of Iraqis and American forces in the sixth month of the American bid to calm Baghdad and the center of the country illuminate the stubborn resistance to a political solution in Iraq, where the government and legislature appear determined to press for sectarian advantage rather than Iraqi unity.

The Shiite-dominated parliament said Prime Minister Nouri al-Maliki should intervene to end the crackdown by U.S. and Iraqi forces on Husseiniyah. The town is a stronghold of the Mahdi Army, the militia loyal to radical cleric Muqtada al-Sadr, and straddles the highway to Baqouba, where U.S. forces are in the second month of a drive to cleanse that region of al-Qaida in Iraq.

State-run Iraqiya television said the Husseiniyah blockade “would have serious consequences on people’s lives there.”