Companies and nationals blacklisted by France for alleged links to Syria's chemical weapons programme denied any wrongdoing on Thursday, telling AFP they were gearing up for a legal challenge. France said Tuesday the 25 entities were suspected of belonging to two "supply networks" for the Syrian Scientific Studies and Research Center (SSRC), which has been repeatedly sanctioned over Syria's chemical programme. It said the six-month asset freeze could be challenged within two months of the decision. Many of the firms based in Syria, Lebanon, China, and France are linked to the Katranjis, a large family originally from Syria's central Hama province. Amir Katranji, one of the named Syrian nationals, said he and his blacklisted company Electronics Katranji Trading (EKT) had "nothing to do with chemical" goods. "We aren't doing anything wrong; we reject this announcement," Katranji told AFP in Beirut, and said his firm was appointing a lawyer. "The announcement says 'suspected of' -- there is no clear evidence. Every industry has electronics in it, and we never worked with the military," he said. Katranji said his family hailed from Hama but had emigrated to Lebanon in 1969. He and brothers Houssam and Maher were all listed in the French announcement, as were EKT's affiliated departments, NKTronics and SmartPegasus. SmartPegasus is named as a France-based firm and was traced to a Paris address registered in 2014 as an import-export company. EKT deals in a wide array of electronic equipment, from mobile phones to alarms and bomb detectors. Also blacklisted were Lebanese national Mireille Chahine, who told AFP she worked in EKT's accounting department, and China-based EKT Smart Technology. - 'Based on nothing' - France also sanctioned Beirut-based ABC Shipping, whose owner Sami Ballout fiercely denied his company was involved in chemical arms development. "We reject and deny this decision... Not only do I not have anything to do with this -- I'm taking legal steps," he told AFP. He suspected the decision may have been linked to a 2016 incident in which ABC Shipping facilitated cargo from China to Beirut that was rumoured to be heading to Syria. Ballout, 48, said the matter had already been cleared up and no charges were pressed. "This decision was taken based on nothing," he said. An office address listed for SmartLogistics appeared to be closed, and two Lebanese numbers were out of service. But one number was active on messaging service WhatsApp and was answered by someone identifying himself as Alaa. "We're in Dubai working on the issue. We're hiring an international legal firm. There's been a mistake or a misunderstanding," he said. Damascus-based companies that were named include Golden Star, the MKH Import-Export firm, and metal-trading company MHD Nazir Houranieh & Sons. Five members of the Syrian Houranieh family were also listed. The SSRC has been hit by sanctions in 2005, 2007 and 2017 for its alleged role in developing weapons of mass destruction. Last year, the US blacklisted 271 Syrian chemists and other officials for ties to the SSRC. It accused the centre of developing the sarin gas deployed on a rebel-held town in northwest Syria in April, which the United Nations and others have blamed on the Damascus regime. Syria has staunchly denied using toxic arms and condemned the French announcement as "lies". France announced its sanctions Tuesday, as 24 nations pledged to create a "partnership against immunity" on chemical weapons. After hundreds of people were killed in chemical attacks near Damascus in August 2013, a landmark deal with Russia was struck to rid Syria of its chemical weapons stash, staving off US air strikes. Despite the agreement, chemical attacks have continued in Syria.