The data collected by the L3+C muon spectrometer at the CERN Large Electron–Positron collider, LEP, have been used to search for short duration signals emitted by cosmic point sources. A sky survey performed from July to November 1999 and from April to November 2000 has revealed one single flux enhancement (chance probability=2.6×10-3) between the 17th and 20th of August 2000 from a direction with a galactic longitude of (265.02 ± 0.42)° and latitude of (55.58 ± 0.24)°. The energy of the detected muons was above 15 GeV.