Washington, United States: All 180 airlines serving the United States have taken the security steps needed to avoid being forced to implement inflight bans on laptop computers, the Department of Homeland Security said Thursday.

But the more intense inspections of carry-on electronics required by DHS at all points of departure for the United States are likely to make airport boarding procedures even longer than before.

DHS spokesman David Lapan said that as of midnight Wednesday, the 180 airlines flying to US destinations, including US carriers, and 280 airports that have direct flights to the US, had all implemented the first phase of tough new security protocols announced by US authorities on June 28.

The protocols were not detailed to the public. But officials said they involve a range of measures including more sniffing dogs, explosive trace detection, swapping of luggage for chemical traces and physical inspection of electronics. 

The measures came in response to increased worries that Islamic State, Al-Qaeda and other jihadist groups are plotting to attack international flights with bombs hidden in consumer electronics.

Airlines and airports were warned that their US services would be cut off if they did not immediately begin toughening their pre-boarding inspections.

"The quick and decisive action taken by airlines, nations, and stakeholders are a testament to our shared commitment to raising the bar on global aviation security," said Lapan.

In response to fresh intelligence that the so-called Islamic State group was trying to develop a bomb hidden in a laptop computer or tablet, US authorities ordered a ban on March 21 on carry-on electronics larger than cellphones on all US-bound flights from 10 airports in eight countries in the Middle East and North Africa.

Since then, all 10 airports and the airlines flying from them have installed new equipment or strengthened procedures to protect against a laptop bomb, and the restrictions have been lifted.

On Wednesday, DHS Secretary John Kelly said that officials had tested a laptop bomb on a real airplane and that the result was that "it destroyed the plane."

Given the constant threat of ever-changing technologies, Kelly said DHS decided to take a more sweeping approach to security.

"Globally, we are raising aviation security as opposed to going after one single threat," he said, speaking in Aspen, Colorado.