Serum Institute of India (SII) on Thursday announced it is pausing clinical trials of AstraZeneca Oxford COVID-19 vaccine candidate in the country, a PTI report stated.

AstraZeneca said it had paused the trials because of 'an unexplained illness' in a participant in the study. However, SII on Wednesday said it was continuing with the trials and had not faced any issues.

SII's latest announcement also comes against the backdrop of the central drug regulator DCGI issuing a show-cause notice to SII for not informing it about AstraZeneca pausing the clinical trials of the Oxford vaccine candidate in other countries, the report said.

"We are reviewing the situation and pausing India trials till AstraZeneca restarts the trials," SII said in a statement.

The Pune-based vaccine maker also said it is following instructions of the Drugs Controller General of India (DCGI), it added.

In the show-cause notice, DCGI V G Somani had asked SII as to why the permission granted for conducting phase 2 and 3 clinical trials of the vaccine candidate in the country be not suspended till patient safety is established, the report added.