Fears about Islamic extremism are rising in nations with large Muslim populations from the Middle East to South Asia and support for radical groups is on the slide, according to a new poll.

Concern about extremism has increased in the past 12 months amid the dragging war in Syria and attacks by Nigeria's Boko Haram, the Pew Research Center said on Tuesday after interviewing more than 14,200 people in 14 countries.

Groups such as al-Qaeda, Hezbollah, Boko Haram and even Hamas, which won elections to take control of the Gaza Strip, are also losing support.

The review was carried out from April 10 to May 25, before the Islamic State of Iraq and the Levant - now renamed the Islamic State - took over the northern Iraqi town of Mosul in a lightning offensive which has seen it seize a large swathe of territory.

In Lebanon, which shares a border with Syria, as many as 92 percent of those interviewed from Sunni, Shia and Christian communities said they were worried about Islamic extremism.

Concern has also risen in Jordan and Turkey, both of which border Syria and have taken in significant numbers of refugees fleeing the three-year war to topple Syrian President Bashar al-Assad, in which extremists have increasingly moved into the chaos.

"In Asia, strong majorities in Bangladesh (69 percent), Pakistan (66 percent) and Malaysia (63 percent) are concerned about Islamic extremism," the Pew report said.

However, in Indonesia, the world's most populous Muslim-majority country, such fears were not shared, with only four in ten people voicing any anxiety about extremism.

An overwhelming majority of Nigerians (79 percent) were against Boko Haram, behind the kidnapping of more than 200 schoolgirls earlier this year, while 59 percent of Pakistanis said they have no love for the Taliban.

Just over half of Palestinians (53 percent) have an unfavorable opinion of Hamas and the figure rises to 63 percent in the Gaza Strip, the report said.