Israel is concerned about the deployment of Egyptian armour in a push against militants in the neighbouring Sinai desert, saying the vehicles' entry wasn't coordinated and is in violation of a 1979 peace treaty, an Israeli official said on Monday.
Prime Minister Benjamin Netanyahu's government has not lodged any formal protest preferring to try and resolve the issue in quiet contacts including US mediation, to avoid worsening ties with Cairo already strained since Hosni Mubarak was toppled by a popular revolt last year.
Egyptian security sources said this week they were preparing to deploy aircraft and tanks in Sinai for the first time since a 1973 war with Israel, in a crackdown on Islamist militants blamed for killing 16 border guards in an 5 August attack.
The US-brokered 1979 peace treaty between Egypt and Israel sets strict limits on military deployment in the Sinai.
The Israeli official, speaking to Reuters on condition of anonymity, said Egypt had already sent "some" armoured vehicles into the desert peninsula and that "Israel is bothered by the entry of armoured vehicles in Sinai without coordination."
Egyptian television footage showed General Abdel Fattah l-Sisi in Sinai addressing troops with tanks and heavy equipment behind them. Other images from his visit broadcast by Egypt's private ON TV showed a row of six tanks and five armoured personnel carriers.
While Israel does not view the armour as a threat, the official said, it wants to make sure it has a say over what weaponry is deployed in the Sinai, which the peace treaty intended as a demilitarised buffer zone.
"There is no precedent for armoured vehicles being deployed in Sinai and certainly not without any coordination," he said.
Israel had urged Egypt to crack down on the militants, and its security cabinet had approved an Egyptian request to use attack helicopters in Sinai two weeks ago, after the Islamist gunmen who attacked Egypt's security personnel also penetrated Israel's border where they were killed.
But local media say Israel was worried coordination with Egypt may suffer after a shakeup this month of Egypt's military, including Islamist President Mohammed Mursi's dismissals of officials Israel had long been in contact with.
In Cairo, Yasser Ali, a spokesman for Mursi, told Reuters security measures in Sinai were "crucial" to Egypt's security.
An Egyptian military source told Reuters the Sinai security sweep was in keeping with agreements reached with Israel a year ago after eight Israelis died in a cross-border attack.
"We don't need to issue a daily report to Israel on the operation as it is a matter of sovereignty and national security," the source went on to say.