German Chancellor Angela Merkel urged the kidnappers of a German woman taken hostage in Iraq to release her immediately and said the government was working "around the clock" to free the 43-year-old archaeologist, Reuters reported. Merkel told the Bild am Sonntag newspaper the government was doing all it could to rescue Susanne Osthoff and her driver, who disappeared nine days ago. "The members of the crisis committee are working around the clock to achieve this," she said. "We are calling on the perpetrators to release her immediately." Merkel's appeal follows reports by magazines Der Spiegel and Focus that an ultimatum, made by the kidnappers in a video which was not broadcast publicly, expired early on Friday. According to the reports, the kidnappers said Osthoff would be killed if Germany did not end all support for the Iraqi government by then. Foreign Minister Frank-Walter Steinmeier said on Saturday Germany had failed to establish contact with the kidnappers.