They were dining at the Sizzling Palate in the town centre when the incident happened on Saturday evening (April 28).
Four of the casualties, who were all women, were treated by paramedics for minor injuries while a fifth was taken to hospital suffering from a neck injury.
Pictures taken at the scene showed at least two police cars were also in attendance along with a number of ambulances.
Huzaifa Chunara, from Manchester, was having a meal with his wife and 12 friends when the ceiling dropped.
“There was no creaking… no indication that it was going to let go,” he told the BBC. He said it landed on his wife and friends but just missed him.
“They were trapped beneath for about 30 seconds.”
Another customer who didn’t want to be identified told the BBC: “We were eating when all of a sudden it just fell.
“There was a table directly underneath and a table on the side, which were hit.
“People panicked, were shocked, had no idea what was happening so the men just got up and tried to lift the ceiling off people.
“There were a good 15 to 20 people that had to actually try and hold the ceiling up but… once people got out from underneath, they put it back on the table.”
A spokesman for the Indian restaurant said it happened in the basement of the three-floor venue, which “continued to trade as normal”.
He added: “A section of a suspended ceiling in the lower ground restaurant came loose from its fixing and dropped.
“A couple of customers sustained some minor cuts and bruising.”