Slovak Prime Minister Robert Fico's life was no longer in danger following an assassination attempt, Deputy Prime Minister Robert Kalinak said on Sunday.

The suspected gunman appeared in court on Saturday after Fico was shot four times last Wednesday, leaving him fighting for his life at one stage.

"He has emerged from the immediate threat to his life, but his condition remains serious and he requires intensive care," Kalinak, Fico's closest political ally, told reporters.

The Slovak premier was shot as he was greeting supporters after a government meeting in the central town of Handlova. 

He underwent a five-hour operation on Wednesday and another on Friday at a hospital in the central city of Banska Bystrica.

"We can consider his condition stable with a positive prognosis," Kalinak said outside the hospital, adding that "we all feel a bit more relaxed now."

Kalinak added that Fico would stay at Banska Bystrica for the moment.

The suspected gunman, identified by Slovak media as 71-year-old poet Juraj Cintula, has been charged with premeditated attempted murder and was held in custody following a hearing on Saturday.

Interior Minister Matus Sutaj Estok said that if one of the shots "went just a few centimetres higher, it would have hit the prime minister's liver".

Sutaj Estok added on Sunday that police were looking into the possibility that the gunman may not have acted alone.

"One version is that the culprit was part of a group of people who encouraged each other to commit the crime," he said, adding the gunman may also have disclosed his intentions to someone.

Citing intelligence reports, Sutaj Estok said that someone had erased the gunman's history and communication on Facebook while he was detained.

The attempted assassination has highlighted acute political divisions in the country where 59-year-old Fico took office in October after his centrist populist Smer party won a general election.

He is serving his fourth term as prime minister after campaigning on proposals for peace between Russia and Slovakia's neighbour Ukraine, and to halt military aid to Kyiv, which his government has done.

Fico leads a coalition comprising his Smer party, the centrist HLAS and the small nationalist SNS party.

Kalinak said the government would carry on without Fico "according to the programme he has outlined".

Slovakia was already sharply divided over politics since the 2018 murder of journalist Jan Kuciak and his fiancee.

Kuciak pointed at links between Italian mafia and Fico's then government, and his murder sparked nationwide protests that resulted in Fico's resignation in 2018.

The divisions deepened further with the pandemic and the war in Ukraine.

Following the attack on Fico, outgoing President Zuzana Caputova and her successor Peter Pellegrini, a Fico ally who takes over in June, tried to quell the tensions.

Following a proposal by Caputova and Pellegrini, several parties have suspended campaigning for European Parliament elections scheduled for June.

But some politicians have been quick to blame the Fico attack on their opponents or media.