Italian police are searching for two men linked to the far-left Red Brigades militant group who are suspected of carrying out an attack on the head of a nuclear energy company, media reports said Thursday.

The suspects, who tried to recreate a former Red Brigades cell in 2000, are thought to be behind Monday's attack in Genoa, when a gunman shot the head of Ansaldo Nucleare in the ankle, before escaping with an accomplice.

The pair are also thought to be linked with a local convict serving time for possessing arms from former Communist countries, ANSA news agency said.

Italy's police chief Antonio Manganelli said all possible leads were being followed.

"We have no evidence on the emergence new Red Brigade groups but that does not mean that it is not possible," he said.

Interior Minister Anna Maria Cancellieri had told reporters on Wednesday that the method used in the attack "in particular the use of a firearm and the preparation, could imply the influence of the Red Brigades".

Police were also investigating the possibility that anarchists or organised crime groups could be behind the attack, she said.

Roberto Adinolfi, a 53-year-old nuclear engineer, was followed by the gunman and shot in the ankle as he left his home in Genoa in northwest Italy.

The gunman escaped on a motorbike with a second man waiting nearby. Police said he used a Tokarev handgun -- a brand used by the Soviet army.

Security sources said the attack was similar to one of the first shootings by the far-left Red Brigades militant group, also against Ansaldo, which is part of industrial giant Finmeccanica.

A source said there was "major concern" that the shooting could be a signal for sleeper cells to carry out more attacks or spark copycat shootings.

A total of four Ansaldo managers were victims of attacks by the Red Brigades in Genoa in the 1970s including one who was snatched from the street and released a few hours later and three who were shot and wounded in the street.

The Red Brigades emerged in the 1970s seeking to create a Marxist-Leninist state through armed struggle and were responsible for a number of murders.

Among their most notorious actions was the kidnapping and murder of Italy's former Christian Democrat prime minister Aldo Moro in 1978.