WASHINGTON (AFP) - The US State Department Monday unveiled sanctions against 13 people and three firms implicated in the nuclear proliferation network set up by Pakistani scientist Abdul Qadeer Khan. The State Department said that even though Khan and his associates have been arrested, prosecuted or convicted it was important to prevent the 16 from resuming proliferation activities and to deter other proliferators. Khan, the father of Pakistan's atomic bomb, has been effectively under house arrest in Islamabad since February 2004, when he confessed on television to sending nuclear secrets to Iran, Libya and North Korea. He later retracted his remarks. "We believe these sanctions will help prevent future proliferation-related activities by these private entities," the State Department said in a statement. The measures will "provide a warning to other would-be proliferators, and demonstrate our ongoing commitment to using all available tools to address proliferation-related activities," it added. "Many of Dr Khan's associates are either in custody, being prosecuted, or have been convicted of crimes," it added. "While we believe the AQ Khan network is no longer operating, countries should remain vigilant to ensure that Khan network associates, or others seeking to pursue similar proliferation activities, will not become a future source for sensitive nuclear information or equipment," it said. Most of those sanctioned have for years been mentioned in the media over their links to Khan: Turkish businessman Selim Alguadis and his firm EKA Elektronik Kontrol Aletleri Sanayi ve Ticaret AS, Pakistani scientists Muhammad Farooq and Muhammad Nasim ud Din, Sri Lankan scientist Buhary Seyyed Abu Tahor, German engineers Gerhard Wisser and Gotthard Lerch, Swiss engineer Daniel Geiges and British businessmen and brothers Paul and Peter Griffin. Set up by Wissar, the South African firm Tradefin Engineering is also on the list which nevertheless does not say whether these individuals or firms have business interests in the United States or retain contacts with US firms. In line with a number of US laws and decrees, the sanctions bar these individuals and firms from obtaining any private or government loans and forbid the US government from having any commercial links with them. The statement mentions other people without listing their nationalities or links to Khan: Kursad Zafer Cire, Shamsul Bahrin bin Rubikan, Shah Hakim Shahnazim Zain and the Turkish firm ETI Elektroteknik Sanayi ve Tikaret AS. "The network's actions have irrevocably changed the proliferation landscape and have had lasting implications for international security," according to the State Department statement. APP adds: Prime Minister Syed Yousuf Raza Gilani on Monday said Pakistan is mindful of its responsibilities as a nuclear weapon state as well as its international obligations. "AQ Khan is a closed chapter", the Prime Minister said in response to the US State Department's announcement that sanctions would be imposed on three firms and 13 people, of which three are Pakistanis and rest are of other nationalities implicated in AQ Khan's nuclear proliferation network. The Prime Minister said, "the sanctions are not against the state or government. US has in fact applauded Pakistan's contribution to promote global non-proliferation", says a Press release issued here.