ANDREWS AIR FORCE BASE, Md., Nov 16 (Reuters) - Israeli Prime Minister Ehud Olmert said on Thursday Palestinian militant rocket fire from Gaza could not be stopped in "one fell swoop", appearing to rule out a massive military push into the strip. One of the heaviest barrages of makeshift missiles fired from the Gaza Strip in months killed a woman and wounded several other people in the Israeli border town of Sderot on Wednesday. That prompted right-wing Israeli politicians to call for a major push into Gaza, which Israel quit last year after more than 38 years of occupation. "The attack was very severe and (Israeli military) activity will continue in order to cut down on Qassam (rocket) fire as much as possible," Olmert told reporters on a flight back to Israel after a trip to the United States. Asked about a wider Gaza operation, Olmert said: "I do not think you can stop Qassams in one fell swoop. There is not one single action that can be taken that would stop them." Palestinian militants often fire rockets from fields in northern Gaza but then quickly disappear into nearby towns and villages. Olmert has said Israel would find and kill those responsible for the attacks on Wednesday.