Britain, the US and Canada have approved a new round of travel restrictions targeting the Iranian regime, including members of the judiciary and prison officials.

The British foreign secretary, William Hague, said on Friday that the punitive measures were aimed at individuals associated with Iran's nuclear programme as well as those involved in the violation of human rights in the country.

"The UK is working closely with its partners to prevent a wide range of individuals connected with Iran's nuclear enrichment and weaponisation programmes from entering our countries. These include scientists, engineers and those procuring components," Hague said in a statement.

"We are also taking action against more Iranians who have committed serious human rights abuses, including government ministers, members of the judiciary, prison officials and others associated with the Iranian government's brutal crackdown on its people since the disputed elections of 2009."

Britain has not released the names of the 50 individuals on the blacklist but it is believed that judges and prison officials who participated in the detention of human rights activists, including those involved in the sentencing of prominent lawyer Nasrin Sotoudeh to 11 years in jail, are affected by the travel ban.

The EU has already imposed travel bans on 32 Iranian commanders, judges and prison officials who have committed human rights abuses but the Foreign Office said the new move was aimed at extending the previous list by adding 50 new individuals from various governmental bodies including Iran's ministry of science, research and technology, the ministry of intelligence, the ministry of justice and the ministry of the interior.

Prosecutors, prison staff and members of the security forces, including the powerful Revolutionary Guard and the police, are also believed to have been hit by the new travel curbs.

Hague insisted Iran "continues to seek equipment and components from around the world for its illicit nuclear programme" and said: "The message to the Iranian government from the UK and its partners is clear: it needs to change its behaviour before it will be treated as a normal member of the international community."

The Foreign Office believes the Iranian government has supported the repression of pro-democracy protesters in Syria and said some of those from Iran's ministry of intelligence who were banned from travelling to the UK had played a role in the suppression of Syrian demonstrations.

Iran's foreign minister, Ali Akbar Salehi, was among those banned from entering the EU but his travel restriction was lifted after an intervention by the European Union in the hope of a nuclear agreement with Iran. Critics of the EU's move say Salehi's travel ban was lifted because Germany wanted to secure the release of two German journalists imprisoned in Iran.

In reaction to the co-ordinated action of the UK, the US and Canada, Potkin Azarmehr, an Iranian blogger based in London, said: "Travel ban on Islamic Republic officials was thought to be one of the effective sanctions which did not harm the people in Iran. If those listed are still able to travel [a reference to Salehi] and receive exclusion because of their positions it will make a whole mockery of the travel ban sanction. The way to get round this sanction for the Islamic Republic will simply be to promote those on the travel ban."

Azarmehr said he was worried that the travel ban imposed on Fereydoon Abbasi-Davani, who has been recently appointed as the head of Iran's atomic energy agency, might be lifted because of his job promotion.

Esmail Ahmadi-Moqaddam, the chief of Iran's national police, Ghorban-Ali Nadjafabadi, former prosecutor general of Iran, Hassan Haddad, a judge in Tehran's revolutionary court, Abbas Jafari-Dolatabadi, prosecutor general of Tehran, Gholamhossein Mohsen-Ejei, prosecutor general of Iran, and Saeed Mortazavi, a former Tehran prosecutor, are among the 32 blacklisted Iranians whose names have already been released by the EU.