The captors of kidnapped BBC correspondent Alan Johnston have promised to release him within 24 hours, a person involved in the negotiations said Saturday. Later, the Islamic militant group Hamas said it had made contact with Johnston's captors in Gaza and was taking "serious and practical steps" to win his release. By seeking the journalist's release, Hamas was apparently trying to avoid alienating the outside world after wresting control of the Gaza Strip. The group is also sending a signal to other armed groups that it intends to impose order in chaotic Gaza. Hamas spokesman Abu Obeida told reporters at a midnight news conference that Hamas "will not allow anyone to attack journalists or foreigners, because they are helping our people." Asked whether force could be used to free Johnston, Abu Obeida said all options were open but stressed Hamas wants to resolve the case "in a way that protects the safety and security of the kidnapped journalist." Johnston, 45, was kidnapped in Gaza three months ago by a group believed to have some links to Hamas, and a message purporting to be from his captors has demanded the release of Islamic prisoners, including a cleric being held in Britain. Hamas has been negotiating with the captors through a mediator. An official involved in the talks, speaking on condition of anonymity because of the sensitivity of the talks, said the captors pledged Friday to release Johnston within 24 hours. In London, a BBC spokeswoman said, "We are aware of the reports, but have not received any firm confirmation of Alan's situation." She added: "We continue to work with everyone involved to try to effect Alan's safe release." She spoke on condition of anonymity under BBC guidelines. Earlier Friday, Obeida demanded that those holding Johnston free him at once. "We will not allow his continued detention," he said. Johnston was seen for the first since his abduction in a video posted two weeks ago on a Web site used by Islamic militants. He appeared calm and said he was being well-treated and was in good health. His disappearance is the longest of any Western journalist abducted in Gaza and has sparked numerous protests and solidarity marches in London and the Palestinian territories. Palestinian officials have said they know where to find Johnston, but have held back on raiding the hideout at Britain's request, for fear of harming him.