“Major incidents” were declared at the Royal Adelaide and Queen Elizabeth hospitals late on Monday after a surge in acute presentations left more than 100 people in emergency departments waiting for a hospital bed.

It is the second time a “code yellow” alert has been issued at the Royal Adelaide Hospital since June.

A major incident alert was also declared at the Flinders Medical Centre in May.

The Central Adelaide Local Health Network said a number of actions had been taken improve bed availability on Tuesday, including delaying elective surgery appointments.

“Rescheduling elective surgery is always a last resort and is done to ensure the safety and wellbeing of our patients,” the CALHN spokesperson said.

“We will work to rearrange all surgeries over the coming days.

“As always, we must prioritise our patients with the most urgent needs and we apologise to anyone who has been affected by the measures currently in place.”

The spokesperson said the major incident declaration was expected to be stood down within 24 hours.

In a letter sent to all network staff on Monday night, CAHLN Executive Director of Operations Brendan Docherty said a major incident was called due to “major demand pressure across the network”.

He said patients were presenting with “increasing complexity and acuity” and the Network Incident Command Centre would be meeting every two hours to find ways to ensure emergency patients get access to beds.

-with AAP