US Colin Powell, who had major differences with hawkish members of President George W. Bush's administration over Iraq, has resigned as US Secretary of State. Powell said he stay on until his successor is confirmed by the Senate. US Bush accepted the resignations of Powell and three other members of his cabinet -- Agriculture Secretary Ann Veneman, Energy Secretary Spencer Abraham and Education Secretary Rod Paige. Iraq Warplanes bombed rebel targets in the restive city of Baquba as violence raged across Iraq, despite a major assault on Fallujah where US-led forces tried to crush rebels prepared to fight to the death. Iraq An audiotape on an Islamist website, purportedly from Iraq's most wanted man Abu Musab al-Zarqawi, urged his supporters to brace for new battles against US forces after the showdown in Fallujah. Iran The UN atomic agency said in a report it had no proof so far of a secret Iranian nuclear weapons program but could not yet conclude definitively that there was no covert activity. UN The UN Security Council will vote to impose an immediate arms embargo on strife-torn Ivory Coast later on Monday, diplomats said. Netherlands Three ethnic Albanians went on trial in an unprecedented case at the UN war crimes court, charged with murder, torture and inhuman acts against Serb and Albanian civilians in Kosovo in 1998. Nigeria Nigeria's central labour movement and a coalition of civil society groups suspended a nationwide general strike due to begin at midnight. Macedonia Macedonian Prime Minister Hari Kostov submitted his resignation to parliament, citing policy disputes and a lack of teamwork within the ruling coalition in the former Yugoslav republic. Namibia With some delays due to a computer glitch, voting got under way in Namibia to elect a successor to President Sam Nujoma, who has ruled the vast southern African country since independence 14 years ago. Australia At least 79 people were injured, two of them seriously, when a high-speed train carrying more than 160 passengers and crew derailed in eastern Australia.