Muslims in London were reacting with anger and frustration to the resurfacing of stereotypes about adherents to their religion following the apparent Islamic State group terror attack near Parliament on Wednesday. The working assumption was that the perpetrator of the driving and stabbing attacks that left four victims dead and dozens more injured was a Muslim before the assailant was even identified.

The entire episode has forced many Muslims living in the U.K. to go on the defensive, the Washington Post reported Friday.

Read: Is London Safe? Attack On UK Parliament Raises Terrorism Security Concerns Citywide

"Why should we keep apologizing? These people do not represent us," one person told the Washington Post. "They do not represent Islam."

In a showing of solidarity with their fellow countrymen, a group of British Muslims have raised more than $25,000 to benefit the victims of the terror attack that included a car being driven by into a group of people on Westminster Bridge before the driver Khalid Masood crashed into the Parliament building, got out and went on a stabbing spree.

Masood's identity was not revealed until about 24 hours after the attack, right around when ISIS claimed responsibility for it. Prior to that, no one other than law enforcement knew who the assailant was, but that didn't stop "Muslim" from trending on Twitter beforehand.

London Mayor Sadiq Khan, who is also a Muslim, released a brief statement following the attack that did not include a reference to any religion. Instead, he simply said it was "being treated as a terrorist attack."

Read: American Killed In London Terror Attack: Kurt Cochran Died On Westminster Bridge

Despite what may seem like an impossibility at times, British Muslims urged people not to associate terror with Islam.

"The targeting of innocents, the murder of civilians, the use of terror against a city — these are all strictly forbidden in Islam," one Muslim who lives in south London told the Washington Post. "I refute their manipulation of Islam and their false justifications for these reprehensible crimes."