Dozens of armed men dotted the crowd in the West Bank city of Abu Dis on the outskirts of Jerusalem, during a weekend event marking the anniversary of a Palestinian military organization.

The men, wearing military uniforms and masks to hide their identities, and toting various rifles and pistols, fired shots into the air at the celebration of the 45th anniversary of the Democratic Front for the Liberation of Palestine, Israel Radio reported.

The DFLP, the third-largest member faction of the Palestine Liberation Organization, is a Marxist-Leninist, secular military organization that broke away from the Popular Front for the Liberation of Palestine in 1969.

In past years, the Palestinian Authority has enforced a ban on armed public displays, but in recent months there has been an increase in such incidents, particularly in refugee camps, where Palestinian security forces have little control.

At least one armed member of the Izz ad-Din al-Qassam Brigades, Hamas’s military wing, appeared at a late-January memorial service for a slain member of Islamic Jihad in the Jenin refugee camp. He was standing on a makeshift stage flanked by members of Islamic Jihad and Fatah’s military wing, the al-Aqsa Martyrs’ Brigade. Two other Hamas members allegedly filmed the incident.

At the time, a source in the Palestinian Authority said that security forces would act to arrest any members of Hamas’s military wing if they received specific intelligence of their presence, as it is forbidden for them to appear in public in the West Bank. However, he qualified that it was difficult to crack down at sensitive events, such as a memorial.