The British Foreign Office warned tourists on Saturday that it believes “terrorists may be in the final stages of planning attacks” . . . Kenya has stepped up its security since it sent troops to pursue al Qaeda affiliated al Shabaab rebels in neighboring Somalia last October . . . at least 30 people have been killed in attacks by suspected militants in Kenya’s North Eastern Province . . . a British citizen and three Kenyans appeared in court on Thursday after being charged with possessing illegal explosive-making material and for conspiring to explode a bomb. . . a large terrorist attack on Kenya would be a major setback to its offensive against al Shabaab . . . increased security in Nairobi reflects how seriously the government is taking recent threats . . . a terrorist attack from Al Shabaab would likely be in the form of simultaneous truck bombings, similar to the 1998 attack on the US embassy.