Both the United States and Britain issued advisories Saturday to their citizens, urging them to leave Afghanistan immediately using commercial flight options.“Given the security conditions and reduced staffing, the Embassy’s ability to assist U.S. citizens in Afghanistan is extremely limited even within Kabul,” a statement issued by the U.S. Embassy in Kabul said.The advisories are consistent with past positions of both countries.In April, the U.S. ordered all embassy staff that can work from elsewhere out of the country.“We have been consistently clear that the security situation is uncertain,” a British Embassy spokesman said.    Violence in Afghanistan has steadily increased since the announcement that foreign forces were going to withdraw from the country.UN Envoy: Afghanistan War in ‘Deadlier, More Destructive Phase’Calls for Security Council action come as Taliban make military gains around countryThe Taliban has attacked several parts of the country and nearly doubled the territory under its control, including overrunning several key border crossings.Targeted killings of journalists, human rights activists, and government officials also have skyrocketed. Dawa Khan Menapal, the director of the Government Media and Information Center (GMIC), was assassinated during Friday prayers in Kabul.Fighting continues to rage in several Afghan cities. On Friday, the Taliban took over Zaranj, the first provincial capital to fall to the militants since the withdrawal of foreign forces.On Saturday Taliban militants overran a second provincial capital, Sheberghan, in Jawzjan province, after weeks of clashes and heavy fighting. The city is home to Afghanistan’s highest ranking military officer, former warlord Marshall Abdul Rashid Dostum.  Social media videos showed prisoners escaping Jawzjan prison as heavy fighting raged around the city.Meanwhile, in Lashkar Gah, the capital of Helmand province, Afghan security forces have wrested control of the city center from the Taliban after intense fighting and heavy airstrikes that killed many civilians and damaged the city’s infrastructure.The U.S. Embassy in Kabul issued a press release Saturday afternoon, condemning the Taliban offensive against cities and calling on the militants to agree to cease-fire and engage in peace negotiations.   “These Taliban actions to forcibly impose its rule are unacceptable and contradict its claim to support a negotiated settlement in the Doha peace process. They demonstrate wanton disregard for the welfare and rights of civilians and will worsen this country’s humanitarian crisis,” the release said.  In a statement Friday to the United Nations Security Council (UNSC), the head of the U.N. Mission on Afghanistan, Deborah Lyons, said at least 104 civilians were killed in the Lashkar Gah fighting in the last 10 days alone, as recorded by the city’s two main hospitals.  “In the past weeks, the war in Afghanistan has entered a new, deadlier and more destructive phase,” she said.  Videos shared on social media showed the city’s market in flames.The Taliban issued a statement reassuring former civil servants and government employees, “including those who worked in the security sector in Nimruz and other provinces,” that they were safe and should not try to flee.News of alleged Taliban atrocities in other parts of the country, however, have forced many to try to escape. A large number of people from Nimruz tried to cross over into Iran, which borders the province, but they were turned back by Iranian border guards.Lyons warned that the war was “reminiscent of Syria recently or Sarajevo in the not-so-distant past,” and she said that without the UNSC’s support, the country could descend “into a situation of catastrophe so serious that it would have few, if any, parallels in this century.”