A fire broke out overnight Sunday at the office of an Israeli NGO that champions human rights in the occupied Palestinian territories, a spokeswoman for the organisation said, with arson cited as a possible cause.
The blaze extensively damaged the Jerusalem office of the group B'Tselem but there were no injuries as the premises were empty at the time, the spokeswoman said in a statement.
"A fire broke out at B'Tselem's office in Jerusalem this evening. None of our staff were in the building," she said.
"Initial reports published by the media indicate that police suspect arson," she added.
"If it is discovered that this was an arson attack, it must be seen in the context of the wave of government incitement and smear campaigns against Israel's human rights groups, and B'Tselem in particular."
But she said the fire would not stop the organisation's work of documenting and exposing human rights abuses under the occupation.
Speaking on public radio, a representative for the fire service did not rule out the possibility of arson.
Although he confirmed the premises had been seriously damaged but no one injured, Israeli police announced one person in the office was slightly wounded.
Yoram Levy, a spokesman for Israel's fire department, stated it has launched an investigation into the cause of the fire.
Israeli Prime Minister Benjamin Netanyahu launched what was seen as a crackdown on leftwing NGOs in December with contentious draft legislation toughening rules on rights groups receiving funds from abroad.
Left-wing NGOs described the move as a witch-hunt.
Currently about 600,000 Israelis live in the West Bank and east Jerusalem. The international community, including the United States, has defined the settlements as illegal and said that Israel is undermining the goal of establishing a Palestinian state living in peace next to it.
An Israeli anti-settlement watchdog group, Peace Now, said that the Israeli government has been planning to build more than 8,000 homes in a strategic area of the West Bank near Jerusalem.
The Palestinians have opposed the settlement in the area saying that it would separate a future Palestinian state in the West Bank from east Jerusalem and drive a wedge between the northern and southern parts of the West Bank.
The Palestinians have claimed the West Bank and east Jerusalem, seized by Israel in the 1967 Middle East war, for an independent state. They have said that the Israeli settlement construction on the lands they have claimed was a sign of bad faith.