A public hearing into a controversial power line project between Edmonton and Calgary has been postponed because of security concerns.

The Alberta Energy and Utilities Board said it has put the public hearing in Red Deer on hold after three incidents in which people at the hearing or board staff were threatened with violence or physically confronted.

"There were physical confrontations, threats of violence, and in one case, there was actual contact," Davis Shermata, a spokesperson for the board, told CBC News on Thursday.

"All three incidents happened right in our hearing room where the hearing was happening."

No charges have been laid. The physical contact was pushing and shoving between a landowner and a board staff member, he said.

Joe Anglin, the vice-chair of a group that represents about 800 landowners, said the board incited the crowd by turning off the microphone when people were trying to speak.

He said the move created a lot of shouting, much of it coming from older people. He said didn't see any shoving.

"No, there was no security problem," he said.

The board has been hearing submissions from the public about AltaLink Management Ltd.'s proposed 500-kilovolt power line that would run through central Alberta, from Genesee substation near Edmonton to Langdon east of Calgary.

The hearing, which began on March 12, was scheduled to run for five to seven weeks. Board staff were hearing submissions five days a week from 9 a.m. to 5 p.m. The hearing has been adjourned twice.

Shermata said the board understands the proposed power line would affect hundreds of landowners in the area and that emotions are running very high.

But he said the board must find ways to guarantee safety for the board's staff and participants at the hearing before it resumes.

Any landowner living within 800 metres of the proposed route can make a submission to the board at the hearing.

The board said it would announce on Monday how it would proceed with the hearing.

With files from the Canadian Press