An incendiary balloon was found in Jerusalem

This is the possibly the second time a jihadist balloon gimmick was discovered in a populated area around Jerusalem:

Police units in Jerusalem responded to a suspicious balloon found in a building site in the central area of Emek Refaim.

[...] Later, incendiary kites and balloons began landing in Gush Etzion, near Jerusalem. Due to the distance and local topography, it is expected that incendiary materials landing in Gush Etzion were sent not by Gazan terrorists, but by Palestinian Authority (PA) terrorists.

This is the first time an incendiary balloon has landed in Jerusalem. However, an incendiary kite landed in a Jerusalem yard in July.

It's entirely likely some PLO jihadists were responsible. But this is also because authorities refuse to enter Gaza and do anything about this.