The weighted average rate swelled by 1.32 percent to 5.7 percent at the end of Friday.
"The rate increased from 4.38 percent the previous week as small and medium banks concluded transactions at higher rates," said the Central Bank on Saturday.
During the week, activities in the interbank market were subdued largely on account of reduced participation by large banks.
"The volumes traded decreased to an average of 79 million U.S. dollars from 127 million dollars in the previous week," said the apex bank.
The number of deals also decreased to an average of 20 compared to an average of 26 in the previous week.