BROOKLYN - More controversial ads about Islam have popped up around New York City subways.

The American Freedom Defense Initiative purchased space next to 228 clocks in 39 stations. Its ads feature varying messages, such as one with the picture of the burning World Trade Center and a quote attributed to the Quran.

The group has already come under fire for posters it displayed in 10 city subway stations last September. Those ads included a message that equated Muslim radicals with savages.

The latest round of ads went up Monday and will run for a month. The MTA says it also sold space last year to competing advertisers urging tolerance.