According to B1A4's management agency, WM Entertainment, the accident occurred around 7PM KST on January 27 near Gapyeong, Gyeonggi-do.
B1A4's car was hit by another car, which was making a lane change.

B1A4 was on its way to 'ICON Concert' held in Inje, Gangwon-do, but it was unfortunately unable to attend the concert due to the car accident.
On January 28, WM Entertainment released an official statement in regard to B1A4's car accident stating, "Members of B1A4 have completed their medical examinations at a local hospital in Inje and were diagnosed with bruises and muscle pain, and they are taking some rest following the diagnosis. We will do our best in order to make members of B1A4 recover quickly. We would like to apologize to all B1A4 fans for causing concern and to the audience who were waiting for B1A4 at 'ICON Concert'."

Here is the full text written by WM Entertainment:
Hello, this is WM Entertainment.
First of all, we would like to apologize for being late in delivering the news to fans who have been worried since the car accident occurred.
On January 27, B1A4 was involved in a car accident on its way to Inje to attend 'ICON Concert'.
We would like to sincerely apologize for delaying the release of an official statement.
The accident happened all of a sudden, and following up with B1A4 members was the most important thing to do, so we thought it was best to get precise check-up done at the hospital in prior to releasing the statement.
Currently, members of B1A4 have completed their medical examinations at a local hospital in Inje and were diagnosed with bruises and muscle pain.
They are taking some rest following the diagnosis.
We will do our best in order to make members of B1A4 recover quickly, and we will put safety of our artists before anything else in the future.
Once again, we would like to apologize to all B1A4 fans for causing concern and to the audience who were waiting for B1A4 at 'ICON Concert'.

(Lee Narin, Credit= 'b1a4' Official Website, '_b1a4official' Twitter, SBS funE)
(SBS Star)