Experiments with the new generation of neutron detectors --- the boron-containing
scintillators placed inside a standard NM64 type neutron supermonitor --- have shown, that
the peculiar high-multiplicity neutron events with anomalously prolonged temporal
distributions of neutron intensity, which have been observed earlier in a set of neutron
monitor installations, are connected with an overload of the gas ionization counters the
monitors have been traditionally build on. The new data permit to state, that this overload is caused by production of a multitude of low-energy neutrons in the core region of extensive air showers with the energies above the knee of primary cosmic ray spectrum --- the effect, which is incompatible with the standard models of EAS development.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 4 (HE part 1), pages 7-10