The US has urged its citizens to be vigilant against possible anti-American violence abroad following the killing of al-Qaeda leader Ayman al-Zawahiri. His death could prompt al-Qaeda supporters or other linked terror groups to target US facilities and personnel, said the state department. Zawahiri was killed by a US drone in the Afghan capital, Kabul, on Sunday. He had helped mastermind the 9/11 attacks on the US in which nearly 3,000 people lost their lives. The 71-year-old Egyptian doctor took over al-Qaeda after the death of Osama Bin Laden in 2011. The killing was confirmed on Monday by US President Joe Biden, who said Zawahiri had carved “a trail of murder and violence” against American citizens.(BBC)…[+]