Two under-trial prisoners died at Chittagong Medical College and Hospital within a span of an hour, said jail authorities on Monday.
The deceased have been identified as Md Rafique, 54, and Babul Mia, 38 of Chandanaish upazila of the district.
With the two fresh deaths, four people have so far died in jail this week.
Dewan Mohammad Tariqul Islam, a jailer of the Chittagong Central Jail, said Rafique, an accused in a case related to a clash, complained of chest pain around 5am after having Suhoor.
Later, he was taken to Chittagong Medical College and Hospital where doctors declared him dead.
Babu, an accused in a Narcotics case, fell sick in the jail within an hour and was taken to the same hospital where doctors pronounced him dead.