Israel is to increase the number of aircraft that will be fitted with the Elop C-Music anti-missile countermeasures system to include a number flying on domestic routes.
Previously the Israeli authorities had mandated that only aircraft on international flights would be required to fit the system.
However, the changing situation in Egypt and a potential flood of weapons into the country following the revolution in Libya are understood to be concerning Israel.
Aircraft operating domestic flights, mainly on the Tel Aviv to Eilat route which passes close to the Egyptian border, will now be brought within the scheme, according to a source familiar with the situation.
El Al, Arkia and Israir will have aircraft on international services fitted first, with Boeing 737s operated by El Al on the Tel Aviv-Eilat route following. Regional aircraft including the ATR 72s and Embraer 195s operated by Arkia and Israir are likely to be fitted with a smaller version of the system.
Installation of C-Music will begin soon after technical difficulties are overcome, said the source. Mixed teams from Elop, a division of Elbit Systems, and the airlines will fit the system.