BAGHDAD (Reuters) – Six bombs struck Shi'ite mosques across Baghdad on Friday, police said, killing at least 28 people and angering Iraqis who blamed local forces now taking over from U.S. soldiers for failing to protect them.

The blasts, which wounded at least 130 people and appeared to target Shi'ite Muslims taking part in Friday prayers, were a reminder of militants' persistent capabilities in Iraq despite the sharp drop in violence over the last 18 months.
In the worst attack, a car bomb struck people praying in the street outside a crowded mosque in northern Baghdad's Shaab district, killing at least 23 people and wounding 107.
One Iraqi at the scene said a car parked near the al-Shurufi mosque in Shaab exploded midway through the service.
“I saw 15 martyrs,” he said.
After the blast, blood soaked the ground and stained prayer mats outside the mosque. The site was littered with abandoned slippers. The charred skeleton of a car sat nearby.
Shi'ite religious gatherings in the past have been targets of Sunni Islamist al Qaeda, which regards Shi'ites as heretics.
U.S. combat forces withdrew from Iraqi cities and towns last month, raising fears that untested local forces, disbanded and rebuilt from scratch since 2003, would be unable to fend off renewed violence, over six years after the U.S.-led invasion.
Another man working at a car park next to the mosque told Reuters TV he had tried to warn the Iraqi army about a suspicious-looking car.
“There was a taxi in the car park that looked suspicious. I called the Iraqi army to take a look, and they said there's nothing wrong with it. Fifteen minutes later, it exploded.”
On the other side of the city, two blasts around the same time went off near a mosque in southeastern Baghdad's Diyala bridge area, killing four people and wounding 17.
Another bomb in Zaafaraniya, southeast Baghdad, killed one person and wounded six. Two more bombs close to mosques in Kamaliya and Alam districts wounded nine people.
Iraqi army and police officials had no immediate comment.
The attacks raise questions about Iraq's future just a few weeks after U.S. combat soldiers withdrew from urban bases and as Washington prepares to pull out all U.S. troops by 2012.
U.S. Defense Secretary Robert Gates, visiting Iraq this week, said the United States may accelerate to some degree its withdrawal plans as Iraq stabilizes.
Iraqi forces are far improved, but they lack equipment and technology as they face off against a dogged insurgency.
There are also growing concerns about potential violence between majority Arabs and minority Kurds in their largely autonomous northern enclave, who have their own army and show no sign of backing down from claims to disputed territories.
U.S. officials say al Qaeda and other Sunni insurgent groups, most active in ethnically mixed areas north of Baghdad, are trying to reignite the sectarian conflict that brought Iraq to the brink of all-out civil war in 2006 and 2007.
This month, several Shi'ite pilgrims died in bomb attacks, but U.S. and Iraqi officials praised the absence of the kind of major bloodshed such events have witnessed in the past as proof of Iraqi forces' success in handling their new role leading urban security.
U.S. and Iraqi officials expect militant attacks to increase in the run-up to national polls in January, in which Maliki is hoping to capitalize on security gains to present himself as a nationalist leader who has brought stability to Iraq.
Opponents are sure to use such attacks as ammunition against Maliki's increasing assertiveness.
“I lay the blame for these blasts on the government and Baghdad security officials,” said Raad Souar, a politician close to the movement of anti-American Shi'ite cleric Moqtada al-Sadr.
“The reason for the high number of casualties is due to the weakness of security in Baghdad,” he said.
Photo: People gathered at the site of a car bomb explosion next to a Shiite mosque in the neighborhood of Shaab in Baghdad on Friday. (AP/ Karim Kadim)-