The health of Tunisian President Beji Caid Essebsi has improved significantly and he has called the defence minister about the situation in the country, the presidency said on Friday.

Essebsi, 92, a major player in the country's transition to democracy since 2011, was taken to a military hospital on Thursday after suffering a "severe health crisis".

"The health situation of the President is in a remarkable improvement... The President held a telephone call this morning with the Minister of Defence about the general situation in the country," presidency spokesperson Said Guarach said.

The elderly head of state was hospitalised last week as well, for what the presidency described as non-serious treatment.

Essebsi has been a prominent figure in Tunisia since the overthrow of veteran autocrat Zine El-Abidine Ben Ali in 2011, which was followed by uprisings against authoritarian leaders across the Middle East, including in nearby Libya and Egypt.

Tunisia set itself on a path to democracy without much of the violence seen elsewhere, although it has been the target of militant Islamists over the years.

On Thursday, two suicide bombers blew themselves up in attacks on police in the capital Tunis, killing one officer and wounding several others.