WASHINGTON (CNN) — Those directing their anger against Muslims in the wake of the terrorist attacks on the World Trade Centre and the Pentagon should be "ashamed," President Bush said Monday.

"Muslim Americans make an incredibly valuable contribution to our country," Bush said. "They need to be treated with respect."

Touring a Washington mosque, Bush said, "the face of terror is not the true faith of Islam."

He also quoted the Muslim holy book, the Quran: "In the long run, evil in the extreme will be the end of those who do evil."

The president’s comments underscored a Muslim group’s reports on Monday of scores of attacks against American Muslims, South Asians and Arabs since the terrorist attacks on New York and Washington last week.

At a press conference, the Council on American Islamic Relations (CAIR) said it had received reports of harassment of Muslim women and obscenities shouted on the street; bombings, car rammings and arson attempts at mosques; and beatings, death threats and possibly even killings.

"We cannot count the amount of calls that we are getting of the general atmosphere of hatred," said CAIR’s Joshua Salaam.

"Many people are calling in, giving us the incidents of them driving down the street and people trying to run them off the road, people shouting at them, obscenities, foul language," Salaam said. "We’re getting calls of people getting fired from their jobs without any reason. And this is what we’re concerned about is now we’re going to have a future of discrimination that is more subtle."

FBI Director Robert Mueller said Monday that "vigilante attacks and threats against Arab-Americans will not be tolerated."

The FBI and Justice Department, he said, are committed to investigating and prosecuting violations of federal hate crime laws.