BAGHDAD, Iraq -- For the second time in two days, suspected Sunni Arab insurgents targeted civilians yesterday with a crude chemical weapon: a bomb attached to chlorine gas canisters that killed two people, sickened 25 and injured eight others.
The attack was the third in a month involving a combination of explosive devices and chlorine. All three attacks seem to have been poorly executed - burning the chemical agent rather than dispersing it - but Iraqi and U.S. officials said they see a pattern emerging, an apparent effort by insurgents to bring a new level of fear and havoc to Iraq as a new security plan for Baghdad takes shape.
Violence around the country yesterday left at least 40 Iraqis dead. A U.S. soldier was reported killed by small-arms fire a day earlier in Baghdad, and a U.S. Black Hawk helicopter was forced to make a hard landing north of the capital amid reports of ground fire, the military said.
The chlorine gas attack took place on the road leading to Baghdad's airport. A car filled with chlorine gas cylinders exploded near a fuel station in a religiously mixed neighborhood.
The tactic was used the day before in Taji, when insurgents detonated a truck holding two chlorine gas tanks. Six were killed, but scores more suffered from nausea, vomiting and irritated eyes.
On Jan. 28, a suicide bomber plowed a dump truck filled with explosives and a chlorine tank into the base of a rapid-reaction force in Ramadi, killing 16 people. The U.S. military said at the time that there were "no indications of any casualties caused by the release of chlorine gas."
The use of chlorine gas weapons in warfare dates to at least World War I, when Germans used them in April 1915 to dislodge French soldiers from trenches. The weapons caused far more injuries than deaths, though small airborne concentrations of the gas can kill within minutes.
The Black Hawk helicopter went down near Taji. "Indications are now - again, it's preliminary, but the indications are now that it was brought down by small-arms fire and RPGs, rocket-propelled grenades," U.S. Army Maj. Gen. William B. Caldwell IV said in an interview with CNN.
The military said another helicopter landed and rescued the nine people aboard the Black Hawk. At least eight helicopters have crashed, been shot down or forced to make unplanned landings in recent weeks.
The Black Hawk was the first U.S. helicopter shot down since American commanders said that they had altered flight patterns and schedules to foil what they described as a heightened focus on aircraft by insurgents.
In Web postings, insurgents have announced plans to train their sights on U.S. aircraft in another front to undermine the security effort. Helicopters have been in increasing use by U.S. troops as a means of avoiding deadly roadside bomb explosions, but officials have said insurgents are finding ways to target them as well.
The bodies of at least 20 unidentified men were found dumped throughout Baghdad, police said yesterday. All were killed by gunfire. A car bomb explosion at a Sadr City market in the late afternoon killed three Iraqis and injured 30.
Several roadside bomb attacks in southern Baghdad killed at least three Iraqis and injured two.
Violence also erupted in the country's predominantly Shiite south, where U.S.- and British-led forces have begun handing control to Iraqi authorities.
In Najaf, home to influential Shiite seminaries and the most revered Shiite shrine in Iraq, a suicide bomber in a Chevrolet Caprice detonated his explosives at a police checkpoint as officers were inspecting his vehicle. The blast spread wreckage, body parts and blood over 30 yards. At least 11 people were killed, including four policemen, and 37 injured, a Najaf hospital official said.
"My car was behind the car which exploded," said Ridha Mayoof, a 40-year-old taxi driver recovering at the hospital from shrapnel wounds. "I saw a huge flame coming out of the car in front of me. Bodies and parts of the car were flying."
In the southern city of Samawa, gunmen ambushed Mohammed Hanoon, the deputy chairman of the provincial council, as he was leaving a mosque after morning prayers. Hanoon was the second member of the council assassinated in two months.
A suspected former member of Saddam Hussein's intelligence services was fatally shot in the southern city of Kut.
Authorities found an unidentified body in a drainage canal near Iskandariya.
Borzou Daragahi writes for the Los Angeles Times. The New York Times News Service contributed to this article.