South Africa reviews security amid "White Widow" reports JOHANNESBURGSouth African security measures are coming under scrutiny in the wake of the Westgate mall attack in Kenya and reports that Briton Samantha Lewthwaite, wanted by Interpol in connection with a 2011 plot to bomb holiday resorts in Kenya, fraudulently obtained a South African passport. 59 Photos Terrorists attack shopping mall in Kenya FBI agents join Kenya mall siege investigation Al-Shabab's violent reach Who is the "White Widow" terrorist? South Africa's ruling party said it instructed security agencies to analyze the attack in Nairobi, which was carried out by Islamic extremist gunmen who stormed the mall and targeted civilians, and improve on South African security in consultation with local and international institutions. At least 67 people died in the Sept. 21 attack in Kenya. Al-Shabab, a Somalia-based militant group, claimed responsibility, saying the assault was retribution for Kenya's troop contribution to an African peacekeeping force in Somalia that dealt heavy blows to the extremists. "This attack has highlighted the need for tighter immigration laws and processes, strengthening of the security features of the South African identity documents and the monitoring of the movement of people in general and suspicious movements in particular," Gwede Mantashe, secretary general of the ruling African National Congress, said in a statement on Sunday. There have long been concerns that authorities are not doing enough to scrutinize the activities of militant suspects who could be networking, recruiting or raising money in South Africa, which is culturally diverse and has the biggest economy on the continent. On a visit to South Africa in 2009, then-U.S. Secretary of State Hillary Rodham Clinton warned that al-Shabab was recruiting young Somalis from South Africa, Australia and the United States to become suicide bombers in its effort to turn Somalia into a "safe haven for terrorism." Last week, Interpol, acting at Kenya's request, issued an arrest notice for Samantha Lewthwaite, who was married to one of the suicide bombers in the 2005 attack on London's transit system. Intelligence agencies believe Lewthwaite used another person's identity to obtain a South African passport, whose last recorded use was in 2011. On Monday, a manager at a real estate company in northern Johannesburg said Lewthwaite had rented a home there between 2009 and 2010. A South African opposition party, the Democratic Alliance, has urged security ministers to brief a parliamentary intelligence committee on the matter. "We cannot sit back and allow South Africa to become a 'destination of choice' for terrorists," the party said in a statement. Brian Dube, spokesman for South Africa's State Security Agency, declined to comment on any investigation into Lewthwaite. "You run the risk of putting into the public domain information which should not be there, and then it becomes self-defeating," he said. "It's important that we continue to be vigilant and on guard and share critical information with our partners in the security environment, both in South Africa and across the world," Dube said. In the wake of the attack in Nairobi, these matters continue to be a cause for concern. The U.S. State Department, however, said U.S. officers working on anti-terror issues were largely prevented from communicating with South African counterparts in 2012, noting the State Security Agency was aggressively enforcing a rule that its foreign branch first screen such matters. In a global report on terrorism, the State Department also said South Africa had introduced a new, more secure passport "aimed at eliminating forgery of passports by organized criminal networks," and had also taken steps to upgrade border security. The report said most big South African cities have hawalas, informal money transfer systems based on Islamic principles that are often poorly regulated. It cited analysts as saying these systems are likely being used to transfer funds to extremists in East Africa, noting that South Africa has a significant Somali community and a presence of al-Shabab sympathizers.