Dozens of gunmen have disrupted a concert by popular Palestinian singer Ammar Hassan in the city of Nablus.
Armed groups say Palestinians should not be having fun now
Shots were fired in the air delaying the start and scuffles broke out when Hassan later cut short his performance.
"This is not the time to have parties like this in Nablus," one of the masked gunmen was quoted as saying.
Hassan became a Palestinian idol when he was runner-up in last year's Superstar 2 competition modelled on the popular Pop Idol format.
He recently performed sell-out concerts in two other West Bank towns, Bethlehem and Ramallah.
Correspondents say the incident is the latest sign of growing chaos in Palestinian areas where gunmen have gained control during the four-year conflict with Israel.
Palestinian policemen did not make any moves to arrest the gunmen, who were allowed to walk away, the Associated Press news agency reported.
AP says Hassan defied burning tires and chants against him to attend the concert, but was ushered off stage by guards to a bullet-proof room after less than an hour.
About 1,500 fans were reported to have showed up to see the singer, who hails from the nearby town of Salfit.
Hassan performed most songs with a political edge
Nablus, like many other Palestinian areas, is starved of popular entertainment because of the rigours of the intifada and Israel's occupation.
The gunman quoted by AP - said to have belonged to the al-Aqsa Martyrs Brigades militant group - said: "We lost a lot of martyrs and lost a lot of friends, and this is not appropriate for Nablus".
Members of the Hamas group reportedly held signs reading "Don't dance on our blood".
When Hassan left early, fans reportedly turned over chairs to demand his return.
A brawl developed between opponents and supporters of the concert, who threw chairs at each other.
"I am depressed. I came to dance and sing and suddenly gunmen surrounded [us]. These people are criminals," said one young person who had crossed several Israeli military checkpoints to attend the concert.