Donald Trump’s so-called "Muslim ban" received its largest blow to date, when a federal judge issued an emergency order against his bar on citizens from seven predominantly Islamic countries from entering the US.Los Angeles district judge Andre Birotte`s temporary ruling states that immigrants who had already been cleared for legal residency in the US should be allowed into the country - a direct contravention to Mr Trump`s executive order which also suspended refugee resettlement in the US for 120 days and barred Syrian refugees indefinitely.Judge Birotte also ruled that validly obtained immigrant visas could not be cancelled, including those issued anyone from the seven barred countries - Syria, Iran, Iraq, Yemen, Libya, Sudan and Somalia - trying to enter the US.His ruling came after at least four other US states moved to limit Mr Trump`s executive order which he issued last week.Judge Birotte ordered US officials to refrain from “removing, detaining or blocking the entry of complainants or any other person […] with a valid immigrant visa” or “cancelling validly obtained and issued immigrant visas” of anyone who arrives from one of the seven nations barred from entering the US by Mr Trump`s order.It followed a lawsuit filed on behalf of 28 Yemeni-born people, consisting of US citizens who lived in America and their family members who remained in Yemen but had received immigrant visas to come to the country, the Los Angeles Times reported.Finding that the plaintiffs were “likely to suffer irreparable harm” if he didn’t act, Mr Birotte instructed that they should be allowed entry in the country.He added that his ruling be applied to anyone trying to enter the US on a valid immigrant visa from the seven countries included in the ban.The strength and impact of Mr Birotte`s ruling is yet to be known. Several federal judges elsewhere in the country have already issued rulings blocking aspects of the executive order, but it is unclear whether they have been followed.Despite three other judges ruling against the order over the course of the weekend, there were concerns that border officers were not complying with their instructions and had continued to detain people.In one ruling, a New York judge ordered a halt to deportations of travellers who arrived at airports with valid visas to enter the US, but reports later surfaced of people being turned back.The state of Virginia also filed a lawsuit accusing Mr Trump of ignoring a court order to halt the travel ban and asked judges to demand the President show why he should not be held in contempt.The US Department of Homeland Security (DHS) also announced that the travel ban would be reviewed. It said it would look actions taken after the US President issued the controversial order after several people alleged they were unlawfully detained by US Customs and Border officers, who began enforcing the travel ban as soon as it was announced.Source: Independent