Q: What are the estimated numbers of volunteers that are coming forth to fight terrorism? Are they isolated in their endeavors in fighting the Islamic state, or are they fighting other terrorist organizations as well? What are some of their countries of origin?

—Eldridge Holland, Atlanta

A: It's believed hundreds of volunteers, including women, from many countries, including the U.S., the United Kingdom, Canada, Spain, France, Germany, Israel and the Netherlands, have volunteered to fight ISIS. An Australian volunteer who was a former member of the Australian Army Reserve was killed in February while fighting with the Kurdish People's Protection Unit. Erik Scurfield, a former British Marine, was killed as part of a group of about 100 Westerners fighting with Kurdish forces outside a Syrian city in early March.

The U.S. hasn’t banned Americans from joining groups fighting ISIS but considers some of those to be terrorist organizations, the Associated Press reported. About 20,000 foreign fighters, including about 3,400 Westerners, have joined ISIS, according to U.S. officials.

Q: How does Israel limit who visits the country as a tourist and who can stay as a student or resident?

—Al Cooper, Atlanta

A: A U.S. citizen needs only a valid passport to visit Israel as a tourist for up to three months. No other "documentation or preparations" are required, Dena Weiss, the spokeswoman for the Consulate General of Israel to the Southeast told Q&A on the News in an email. Student visas are issued to those interested in studying in Israel with proper documentation, which includes "the admissions letter from the accredited school/university and proof of a departing flight ticket purchase," she wrote.

Andy Johnston wrote this column. Do you have a question about the news? We’ll try to get the answer. Call 404-222-2002 or email q&a@ajc.com (include name, phone and city).