THE HAGUE -- Dutch Prime Minister Mark Rutte has been given extra security over fears that he may be the target of an attack or kidnapping by a criminal gang, CNN said quoting local media reports.

Rutte has been followed by so-called spotters linked to a drug gang, the De Telegraaf newspaper reported.

Telegraaf journalist Mick van Wely told broadcaster NOS the matter was being taken "very seriously".

NOS confirmed the report but Dutch authorities declined to comment.

The reported threat follows the murder of prominent Dutch journalist Peter R de Vries, who was known for investigating the criminal underworld in the Netherlands.

The shooting in July stunned the country, where gun violence is rare but killings linked to organised crime have become increasingly common in recent years.

Outside parliament on Monday, as he arrived for coalition talks, Mr Rutte told journalists he would not comment on the reports. "Safety and protection are issues never to be discussed in public," he said.

There was no comment from Dutch prosecutors or security authorities either.

In office since 2010, the conservative prime minister is fond of cycling and is often seen riding to appointments in the Hague with little or no security in sight.

The Telegraaf said Rutte had been protected with "visible and invisible measures" since the threats had become known.

Telegraaf journalist van Wely said "spotters" linked to a drug trafficking network known as the Mocro Mafia had been seen near Mr Rutte.

"That is so worrying for the security services," he told NOS.

In the criminal world, spotters are people who gather intelligence in preparation for a criminal act, such as an attack or kidnapping.

Dutch far-right leader Geert Wilders, who is usually an ardent critic of Rutte, wished him well, calling the reports "terrible".

Rutte vowed to get tough on criminal gangs after the murder of de Vries.

De Vries had been advising a former gang member, Nabil B, who was testifying in the trial against Ridouan Taghi, described as the Netherlands' most wanted criminal.

The Moroccan-Dutch suspect and his associates are currently on trial for murder and drug trafficking.

The case has put the Netherlands on edge after Nabil B's previous lawyer, Derk Wiersum, was assassinated in front of his Amsterdam home in September 2019.

It has heightened concerns about the criminal underworld in the country, which one police union chief compared to a "narco-state" in 2019.