Security forces loyal to Palestinian President Mahmoud Abbas have set fire to the parliament building and offices of Hamas Prime Minister Ismail Haniyeh in the West Bank city of Ramallah.
There were no immediate reports of injuries. The prime minister's office is not occupied because Israeli travel restrictions prevent Mr. Haniyeh from traveling to the West Bank from Gaza.
In a separate incident, Hamas member of parliament Khalil al-Rabaei was kidnapped by masked men in Ramallah.
Earlier on Monday, a member of Hamas was killed when the two sides clashed at a funeral procession for a Hamas activist who died after an earlier clash.
Tensions between the rival security forces have been escalating in recent weeks over President Abbas' call for a referendum on Palestinian statehood that implicitly recognizes Israel.
Hamas, which is pledged to Israel's destruction, opposes such a referendum.