Pakistan has foiled a major terror plot, seizing three bomb-laden vehicles and arresting three suspected suicide attackers near the capital just days after an al-Qaida-claimed assault on the Danish Embassy, officials said Friday. Authorities ramped up security near the sprawling enclave where most foreign diplomatic missions in Islamabad are located. The US Embassy strongly advised Americans to limit nonessential movement in the city and nearby Rawalpindi. An Internet posting Thursday, purportedly from al-Qaida in Afghanistan, claimed responsibility for Monday's bombing outside the Danish Embassy that killed six people, including one Dane. The terror group threatened to "rain" more attacks on countries where cartoons are published of the Prophet Muhammad. The images carried in various Danish and other Western newspapers over the past three years have sparked periodic unrest in the Muslim world.