Migrants carry belongings
© Philippe Huguen/AFP via Getty ImagesMigrants carry belongings as they walk to board buses in Grande-Synthe, northern France
Many of those surveyed thought some refugees were terrorists.

Migration has grown at a worrying level, according to a global survey, with citizens of Turkey, Italy, Sweden and Germany the most concerned about rising levels.

Three-quarters of those who took part in the Ipsos Institute poll said the number of migrants in their country had grown too much over the past five years. That's a slight fall from the same survey in 2016, when the figure was 78 percent, and down from the 2015 figure of 82 percent, according to France's Le Figaro.

Turkey topped the list of countries with concerns about migration, with 78 percent of respondents saying the increase was too large, followed by Italy (74 percent), Sweden (66 percent) and Germany (65 percent). In France, 58 percent said they felt immigration had increased significantly.

According to the findings, an overall 21 percent of people consider immigration to have had a positive impact on their country. However, that figure was just 14 percent in France (a slight increase on the 2016 figure of 11 percent) and 18 percent in Germany, which goes to the polls on September 24.

The British have a more upbeat view of immigration, according to the poll, with 40 percent seeing the positive side. Canada and the U.S. had similar results, with 38 percent and 35 percent saying migration had benefits.

People in most countries still "strongly agree" or "somewhat agree" with the suggestion that there are terrorists in their country who claim to be refugees, according to Le Figaro.

The survey was carried out among 18,000 people in 25 countries.