Inspired by my post on July 31st regarding the OIC denouncing terror tactics, I resorted to Wikipedia to look up the three largest Muslim organizations in the United States and to find out whether or not they have issued statements condemning terrorism.
The largest Muslim organization in the United States, the Muslim American Society, has issued this:
“MAS Freedom completely condemns the taking and killing of South Korean Christian hostages in Afghanistan as not only a gross violation of the human rights of these captives, but also a horrible violation of the norms of basic human decency. These actions are completely contrary to the basic tenets of Islam, and for the sake of our Lord, we implore those who have taken these hostages to return them safely to their loved ones, and to stop this madness.”
MAS Freedom is the civic and human rights advocacy entity of the Muslim American Society (MAS).
The second-largest Muslim organization in the United States is the Islamic Society of North America. They said this:
Plainfield, IN 7/10/07 – The Islamic Society of North America (ISNA) condemns in the strongest terms the recent acts of terrorism in Glasgow, London and Yemen. We reaffirm our long-standing, unqualified condemnation of all acts of terrorism and all acts of violence committed against the innocent, and our denunciation of religious extremism and particularly the use of Islam to justify terrorism in any of its forms. We sympathize with the victims of these senseless attacks and offer our heart-felt condolences to the families who have lost their dear ones.
We point out that the persons responsible for terrorist attacks often make no distinction as to the religion of their victims. Muslims – in Iraq, Jordan, Afghanistan, Pakistan and elsewhere – have suffered and died at the hands of other Muslims who consider them to be traitors, apostates or sinners. ISNA, and mainstream Muslims all over the globe, reject such extremism aimed at non-Muslims and Muslims alike.
We are grateful to all those working sincerely to protect America from terrorism We encourage Muslim Americans to continue to help safeguard the security and well being of this country and its people, and be constantly vigilant against those who act violently or even demonstrate a desire to inflict harm. We applaud the Muslim community in Southern California that reported to the FBI on a visitor to their mosque who spoke of wanting to commit violent acts. Muslim Americans must work in cooperation and trust with fellow Americans to defend against terrorism in our country and abroad.
The third-largest Muslim organization in the United States is the Islamic Circle of North America. Here’s what they said:
The Islamic Circle of North America (ICNA), a grassroots organization of American Muslims, condemns the train blasts in Mumbai, India that has killed about 183 people and wounded more than 700. In a statement, ICNA president Dr. Khurshid Khan said: “The train blasts in India are inhumane and are barbaric acts. We express our strongest condemnation and anguish at the perpetrators ,whosoever may be behind this heinous and cowardly attack”. We join all Indians and people of conscience around the world in calling for identifying the culprits and bringing them to justice. We also express our deep condolences to the victims and their families. ICNA continues to reiterate its stance against the usage of violence against innocent people anywhere in the world.
Islam, much like Protestantism, does not have a Pope-like figure as worldwide head of their religion. Much like Protestantism, it has no single clerical body or organization for training its preachers. So you’re never going to see a Muslim “Pope” issue a condemnation of terrorism. You might as well complain that Protestants don’t denounce terrorism.
He’s not a a Pope, but [and this is from Wikipedia] Muhammad Sayyid Tantawy is the Grand Imam of Al-Azhar Mosque and Grand Sheikh of Al-Azhar University in Egypt. He has been described as “perhaps the foremost Sunni Arab authority”, “acknowledged as the highest spiritual authority for nearly a billion Sunni Muslims”, and “a supreme authority.”
He has taken a line against Suicide bombings, and unlike his compatriot Yusuf al-Qaradawi, he has condemned the use of suicide bombings against Israelis, rejecting the argument that all Israelis were legitimate targets because at some stage they would all carry a gun. In 2003 he called suicide bombers “enemies of Islam”, adding “people of different beliefs should co-operate and not get into senseless conflicts and animosity. Extremism is the enemy of Islam. Whereas, jihad is allowed in Islam to defend one’s land, to help the oppressed. The difference between jihad in Islam and extremism is like the earth and the sky” 
Speaking after the September 11, 2001 attacks he said “It’s not courage in any way to kill an innocent person, or to kill thousands of people, including men and women and children.” He said that Osama bin Laden’s call for a Jihad against the west was “invalid and not binding on Muslims”, adding “Killing innocent civilians is a horrific, hideous act that no religion can approve”. He said the Qur’an “specifically forbids the kinds of things the Taliban and al-Qaida are guilty of”. 
I hope this convinces at least someone, somewhere, that the majority of mainstream Muslims denounce terrorist tactics.