BAGHDAD, Iraq — Five people were killed when two bombs struck separate Shiite targets in Baghdad today, a day after a double car bombing tore through the stalls of a market crowded with Shiites elsewhere in the capital leaving 88 dead — the bloodiest attack in two months.

The military announced the deaths of two more U.S. troops, including a Marine who died Sunday from fighting south of Baghdad, raising the weekend death toll to 28 as American casualties mount ahead of a U.S.-Iraqi security push to try and secure Baghdad.

An American soldier also was killed Monday in the volatile Anbar province west of the capital, the military said.

The first blast today occurred when a parked car bomb exploded at 9 a.m. near the Finance Ministry, which is run by Bayan Jabr, a Shiite and former interior minister. One civilian was killed and four other people were wounded, including a ministry guard, police said.

A bomb planted under a car exploded about 45 minutes later in the predominantly Shiite commercial district of Karradah in downtown Baghdad, killing four people, including a woman and a 7-year-old boy, and wounding seven other people, police said.

The blast collapsed part of the wall of a brick building, leaving a ground floor apartment exposed and a mass of rubble and mangled cars in the alley.

"Why are the insurgents detonating bombs near our houses every day? Everyday we have a blast, what have we done wrong? May Allah curse everybody who hurts the people," an unidentified elderly woman shrouded in black said as she stood amid the wreckage.

The attacks have battered Shiites during one of their holiest festivals and were the latest in a renewed campaign of Sunni insurgent violence before a U.S.-Iraqi push to secure Baghdad. The first of the 21,000 extra U.S. troops being sent to help quell the violence have started to arrive in Baghdad.

Separately, the U.N. refugee agency said today that men allegedly wearing uniforms of the Iraqi security forces abducted a group of 17 Palestinian refugees from a building rented by the agency in Baghdad.

"UNHCR is very concerned and is seeking information on the Palestinians' whereabouts from Iraqi authorities," the agency's spokesman Ron Redmond told reporters in Geneva, Switzerland.

Some of the Palestinians were released later today, he said. But Redmond was unable to say how many and how they were released.