BAGHDAD - Gunmen wearing headscarves and wielding assault rifles, rocket-propelled grenade launchers, and pistols robbed a gold-jewelry market in broad daylight Tuesday, killing 15 people in the most brazen example of Baghdad street crime that has soared as sectarian fighting ebbed. Authorities blamed al-Qaeda in Iraq.

"The fingerprints of al-Qaeda are obvious in today's heist," said Maj. Gen. Qassim al-Moussawi, Baghdad's chief military spokesman. He said the terror group had been suffering from money shortages and had been planning robberies as a way to fill its coffers.

Officials attribute at least part of the past year's crime wave to terror groups looking for new ways to finance operations, and insurgents adept at launching attacks against military targets are now using their skills to make money instead.

Jewelry stores, currency exchanges, and banks are frequently targeted, though insurgents have also been known to attack oil pipelines to siphon off oil for resale.

Tuesday's heist began when the attackers set off a roadside bomb near the gold shops, killing four bystanders and wounding three, police said. Minutes later, gunmen riding in five or six vehicles swept in, carrying rocket-propelled grenade launchers, rifles, and pistols, witness Mohammed Elaiwi Nassir said.

The gunmen fired shots in the air and threw percussion grenades to frighten off bystanders, he said.

As one of their vehicles blocked the street to prevent a rescue, the gunmen opened fire on 12 shops, killing nine gold-shop owners or their workers and two bystanders, police said. The gunmen then scooped up the gold and fled. The value of the stolen gold was not known or revealed.

"The attack lasted about 15 minutes," Nassir said, "during which only one policeman showed up, but he was shot in his shoulder and leg by the attackers. After 30 minutes, the security forces came."

Some shop owners had AK-47 rifles, not unusual in a country that has seen so much violence and where people often rely on themselves for protection. But the attack happened so quickly, they had little chance to use them.

An Iraqi official said documents seized during an April raid resulting in the deaths of the two top al-Qaeda in Iraq figures revealed instructions to rob banks, jewelry stores, and exchange houses as a way to finance the group's activities.