Argentina\'s capital was crippled for a fourth day Tuesday by a metro strike that shut down the city\'s subways and left roads gridlocked with commuters looking for alternate routes. The metro workers union is threatening to extend its strike if their wage demands are not discussed -- and the city and federal government are pointing fingers at each other over who should handle it. The 2,500 workers are demanding a 28 percent raise in pay, but union leader Nestor Segovia said \"no one has called us to negotiate.\" \"There will be no subway for a long time unless we receive a fast and targeted response,\" Segovia said. Argentina\'s federal government said in January it was turning over the management of the metro to the city. But Buenos Aires mayor Mauricio Macri, a top opposition leader and aspiring presidential challenger in 2015, is refusing to take it on, saying federal authorities must first turn over the funds necessary to improve the system. Meantime, residents trying to get to downtown Buenos Aires waited in endless lines at bus stops while drivers found themselves stuck in gridlocked traffic. \"For me, it is a disaster,\" complained Beatriz, a 55-year-old English teacher, while waiting in central Buenos Aires for a bus that must go through much of the city. The teacher explained she was scheduled to teach a class in the north of the city, one in the center, and then a third back up north. \"I don\'t know how I will do it,\" she fretted. Carlos, 25, who lives in a nearby suburb, said his 15-minute train and subway commute took three times as long by bus on Tuesday. A parking attendant, he was waving a sign to entice drivers into the lot where he works. \"Four of the five floors (of the garage) are already full. Everyone came to work by car,\" he said. Others tried to beat the traffic on bicycles or just walked. A free program created by Mayor Macri that posts bikes for public use in 22 spots around the city was swamped Tuesday. \"Every day we get about 30 people looking for bikes,\" said one employee at a post in downtown Buenos Aires, \"but today there have already been 110.\" Argentina\'s capital has a population of three million, but the metro area sprawls on to the horizon and has more than 12 million people.