The new ‘‘mayor’’ of Al-Katarrah, a bustling commercial and residential neighbourhood in central Baghdad, is a 29-year-old Marine lieutenant from Totowa, New Jersey named Adam Macaluso.Five days ago he led his platoon into the city to fight the Iraqi army. Sunday night, he walked the streets to explain to edgy residents that his Marines were here to help guard against looting. He asked a group standing under a lamppost if they had any questions.‘‘What is going to happen to the Iraqi dinar?’’ one man asked, stumping the young officer. ‘‘I’m not a banker,’’ he explained later that night to the commanding officer of Charlie company of the 1st Battalion, 7th Marine Regiment. ‘‘What am I supposed to tell them?’’To fill the vacuum left by the fall of Saddam Hussein’s government, the Marines have divided the city among young officers like Macaluso, directing them to try to quell lawlessness and gather up weapons stashed throughout the city.They call themselves ‘‘mayors,’’ but the Marines put in charge say they expect their term of office to be brief, and that their goal is to help prepare the Iraqi people to lead themselves.‘‘Its one of the hardest things I’ve ever been asked to do, because I have almost no training to fall back on,’’ said Lt Michael Cerroni of Charlie company. ‘‘Its like local government.’’ Although interpreters are attached to each battalion, they are in high demand, so the Marines ask residents who speak English to help.He drives around the neighbourhood in an ambulance that his troops commandeered from a looter who had stolen it. ‘‘The people are bringing me a computer today so I can keep database of names of the people we’ve met, and those who are helping police the area,’’ he said.His constituents’ biggest concern is security, but with a platoon of around 40 Marines, he said, it’s not possible to keep all of the streets safe. So he is helping residents to establish an informal police force, allowing some of them to carry weapons to police their own streets.‘‘Once the power goes back on, 75 percent of our problems go away,’’ said Capt Tom Lacroix, who explained that much of the looting and random gun shots occur at night when the streets are pitch black.Residents have helped Cerroni by pointing out homes of several Iraqi military officers who live nearby and once ran roughshod over their neighbours.‘‘We have nowhere to live, our home was destroyed by the American bombing. Can we move into the apartments on the river that the government abandoned?’’ asked a middle-aged woman when Macaluso took his platoon on a patrol.‘‘It could be dangerous,’’ said Macaluso, now surrounded by more than a dozen people. ‘‘If people think you are looters they may shoot at you. It is better to wait. I can’t tell you yes or no, yet.’’At such meetings, taking place throughout the city over the past few days, miscommunications are commonplace. One Marine captain said he was shocked when an Iraqi man leaned over to give him a kiss on the cheek.