Fans of pop star Kylie Minogue are waiting to hear whether two tour dates cancelled after the singer fell ill will be rescheduled.
Minogue had planned to play six dates in Manchester
A spokesman for the singer said it was "not clear" when an announcement would be made, as promoters are still waiting for news of her recovery.
On Saturday, Minogue stopped a concert at the MEN Arena in Manchester after an hour, telling fans she had a cold.
Shows on Monday and Tuesday were later cancelled on doctors' orders.
It is not thought that performances on Thursday and Friday will be affected.
Minogue, 38, launched the UK leg of her Showgirl Homecoming Tour on New Year's Eve, following her recovery from treatment for breast cancer.
Her spokesman said: "Kylie has been diagnosed by doctors as having a moderately severe respiratory tract infection and doctors have insisted that she not perform in the immediate future."
A recorded message on the MEN Arena hotline said ticket-holders would be contacted regarding the cancelled shows shortly.
"Customers are advised to keep hold of their tickets as these will remain valid for any new date announced," it continued.
It is not yet known whether Saturday's concert will also be rescheduled.
Kathryn Scott, from Halifax, who was at the concert, told the BBC News website she was "disappointed".
"I don't even think she was actually on stage for an hour, as she kept going on and off for long breaks.
"She just said to us 'don't worry, I've just got a cold', but obviously she couldn't go on.
"She was obviously full of cold, and none of us would want to perform if we felt like that. Everyone was fine about it, we just clapped, because we all know how ill she has been.
"I wish she had just cancelled altogether."
Kevin Winder, from Manchester, said he enjoyed the show despite it being cut short.
"Kylie came on the stage and looked fine when she sang Better The Devil You Know, but then she said she had a sore throat and croaked.
"I saw her in concert in Perth and on New Year's Eve, so I know she completely missed out the second 'act' when she came back on stage after a short interval.
"She did another song in her leopard-skin outfit, but then motioned to the band not to start up again. It was then that she told us she was really sorry but she couldn't go on.
"But she went on to do an impromptu version of Got To Be Certain, then sang Kids with her sister, Dannii, which brought the house down.
"She gave it her best shot. She was an absolute star."
Mr Winder added that MEN Arena management announced the show would either be rescheduled or refunds would be given.
The singer began the run of concerts in Manchester on Friday.
Minogue had been forced to postpone her original Showgirl world tour after her breast cancer diagnosis in May 2005.
She underwent surgery in Australia two days later and finished her chemotherapy in December 2005.
It had been hoped she would also play at this year's Glastonbury festival, after pulling out of a headlining slot in 2005 following her cancer diagnosis.
But earlier this month festival organiser Emily Eavis told BBC 6 Music Minogue was too busy to join this year's line-up.
Minogue's record company, Parlophone, has also said she is working on material which could be released in 2007.
Were you at the concert or do you know someone who was?
Just returned home from the concert. Kylie was incredibly brave to try to continue with the concert as long as she did. I would have been happy for her to mime through the rest of it, but only Kylie knows how ill she feels.
Allan Bird, Warrington
Just got home from the MEN, disappointed not to have seen the full show but Kylie's health comes first. The performance she gave was fantastic and she obviously did not want to let her fans down. She did say that the fans should not worry and it was just a cold.
Lizzie, Bury, Lancs
Kylie performed for just over the hour and it was obvious she was not right. Not sure if we will get money back or option to see her again? Really wanted to see her concert she is so brave after what she has been through.
Matt Berrey, Droitwich
Kylie love you loads you are a genuine star. Get better soon
I paid £55 each for 6 tickets, it's a total disgrace. She said she was ill after the first song so she should have given up then rather than give the audience a half hearted 30 minutes.
Mike Edge, Manchester
Just been to the concert. Gutted! Kylie looked genuinely upset to be pulling out, and her sister joined her for the last song, a version of Kids. Still can't believe it, hope she gets better soon.
Claire Davies, Manchester, UK
Just heard from my wife and her friends who have travelled up to Manchester today from Wiltshire. They are all devastated - they've waited for years to see her. Hope Kylie makes a speedy recovery
Matt, Chippenham, Wilts