You can start with this website http://nigeria.usembassy.gov/ A letter of invitation is usually advised. They may also need to show strong ties to their country, such as family, a job, home, a bank account.
Quick Answer. Over one billion Muslims live in Asia, which makes it the continent with the highest Muslim population. Indonesia is the country with the largest Muslim population, with 209 million people. Continue Reading.
For example, India, a Hindu-majority country, has the third-largest population of Muslims worldwide. The Muslim population of Ethiopia is about as large as that of Afghanistan. China has more Muslims than Syria; Russia is home to more Muslims than Jordan and Libya combined; and Germany has more Muslims than Lebanon.