The daily TPR, which stood at 14 per cent on Tuesday, rose to 17.50 per cent on Wednesday and touched 20 per cent on Thursday.
The state capital district has been recording a high number of daily cases and for the second day in succession it crossed 3,000 cases to reach 3,404.
There were over 1.57 lakh people under observation across the state.
The day also saw 21 Covid deaths taking the total death tally in the state to 50,369.
Amid Covid surge in the state, the staging of an open dance performance by about 600 women by the Thiruvananthapuram district CPI-M, invited huge criticism by the state Education Minister V. Sivankutty who said it was an event which could have been avoided and there was an error of judgement on holding that.