Hours after two policemen and 10 others were killed Wednesday in a shooting at the Paris offices of French satirical news magazine Charlie Hebdo -- an apparent attack by Islamic militants -- moderate Muslims have taken to Twitter to condemn the killings and deny any association between their faith and that of Islamic extremists.

“All day today, I've seen tweets and press releases from Muslim leaders from across the world, and Muslim religious institutions, condemning the Charlie Hebdo attacks. They're not really obliged to, in my opinion,” H.A. Hellyer, a nonresident fellow with the Project on U.S. Relations with the Islamic World at the Center for Middle East Policy at the Brookings Institution, told International Business Times in an email. “We haven't seen the calls for Buddhists worldwide, for example, to condemn radical Buddhists in Myanmar.”

And when prominent Muslims do make public statements, he contended, their voices are rarely heard.

“Each time a terrorist atrocity takes place, the condemnations of Muslim mainstream figures are barely registered,” Hellyer said, pointing to recent statements by the Mufti Emeritus of Bosnia, French Muslim leaders, the Azhar University and Muslim public intellectuals who have condemned the attacks.

“And yet, we're still doing stories about ‘Are moderate Muslims speaking out?’” Hellyer said.

Some moderate Muslims reacting on Twitter are using the hashtag #JeSuisCharlie – which translates to “I am Charlie” --  to condemn the attack. Some are outraged over what they see as an assault on free speech; others are concerned Muslims will be linked to an attack committed by extremists and become the target of discrimination.

A similar sentiment was heard after a lone gunman with extremist Muslim ties held 18 people hostage at a café in Sydney, Australia, on Dec. 15. That attack prompted the hashtag #illridewithyou to trend worldwide after anti-Islamic tweets were sent and the Australian Defence League, an ultra-right-wing group, threatened violence.

Below are some tweets from Muslims worldwide after the Charlie Hebdo attacks in Paris: