One man arrested over alleged plane terror plot released


Dubai-based Emirates, the largest Mideast carrier, said it was cooperating on the additional security procedures but did not say whether it is involved in the investigation.

Australian police, however, have not named the airline that was allegedly targeted in the plot - which authorities say was inspired by Islamist extremism - nor have they identified the manner in which the attackers planned to bring down the aircraft aside from noting it involved an "improvised device".

One of the Sydney men arrested in connection with an alleged terrorist plot to bring down a plane has been released without charge.

The four men who were arrested - Khaled Khayat, Mahmoud Khayat, Abdul El Karim Merhi and Khaled Merhi - reportedly have deep connections to Islamic State.

The men detained in counter-terrorism raids on the weekend may have already made an attempt to smuggle their homemade bomb onto an worldwide flight prior to raids, law enforcement officials have told 7.30.

Two other USA officials, also speaking on condition of anonymity, said communications between the alleged plotters in Sydney and members of IS in Syria were intercepted by a foreign intelligence service.

One US official said the plot was "fairly well along" when it was disrupted by Australian authorities.

"They have made this disruption only three days after hearing a tip-off, presumably from a partner agency overseas, that attack-planning by this cell was imminent", Ms Carroll said.

Abu Dhabi's Etihad Airways said on Tuesday it was helping Australian Federal Police with an investigation that police began into an "Islamic-inspired" plot to bring down a plane and resulted in stricter security screening at Australian airports.

The US officials declined to identify the service and United Kingdom officials refused to confirm or deny playing a role in detecting the plot. The target, the other official said, appeared to have been a commercial flight from Sydney to the Gulf.

"Etihad is complying fully with the enhanced security measures at airports in Australia and monitoring the situation closely", the airline said, without giving further details.

Prof Barton said the conspiracy was "clearly the most sophisticated terror plot" Australia had ever seen, but it likely would have failed.

"The security measures at the airports will be in place for as long as we believe they need to be, so it may go on for some time yet", said immigration minister Peter Dutton.

According to Agence France-Presse, 13 plots - including the most recent - have been prevented in Australia in the past few years and 70 people charged.