Officials said the man did not appear to be targeting Trump or others involved in the trial
Twelve bodies were recovered from Clifton beach on Wednesday night and six more bodies were recovered on Thursday morning, Dawn online reported.
A body was also found at Hawks Bay on Thursday.
Rescue efforts are still underway to recover the four missing bodies from a total of 23 people who drowned on Wednesday.
Thousands of people turned up at the city beaches on the second day of Eid despite the administration-imposed ban under Section 144 on entering or bathing in the sea.