A protester, demanding the criminal indictment of a white police officer who shot dead an unarmed black teenager in August, sits in her vehicle outside the Ferguson Police Department in Missouri Nov. 21, 2014. Reuters/Adrees Latif

Two men who were reportedly suspected of planning to detonate a bomb during protests in Ferguson, Missouri, have been charged with federal firearms offenses.

The men allegely planned to detonate an explosive soon after a grand jury announced its decision on whether to indict officer Darren Wilson in the shooting death of Michael Brown, Reuters reported.

The two suspects were identified as members of the New Black Panther Party, the St. Louis Post-Dispatch reported, citing police sources. Federal authorities also reportedly searched two homes as part of the investigation.

A team of nearly 100 federal law enforcement agents arrived in St. Louis area Friday, amid concerns about potentially violent protests erupting in the event that the Ferguson officer is not indicted over Brown's killing, which triggered racially charged protests in and around the St. Louis suburb.

"The raids yielded information that both men had planned to obtain illegal weapons to do harm to law enforcement and the public," the Post-Dispatch reported.

The grand jury, which has been hearing testimony from witnesses for the last three months, is still reviewing evidence in the case of Brown's Aug. 9 shooting death, a spokesman for St. Louis County Prosecutor Bob McCulloch, said, according to the Associated Press.

Ed Magee reportedly said that the time, date and place for a news conference where the decision will be announced have not been decided.

President Barack Obama urged Ferguson residents to keep any protests peaceful, while Brown’s family also called for calm in the St. Louis suburb. Gov. Jay Nixon signed an executive order Monday activating the National Guard and declaring a state of emergency, ahead of the jury’s decision, to prepare for the possibility of “expanded unrest.”

"Hurting others or destroying property is not the answer," Michael Brown Sr., said in a video released by the group STL Forward, according to AP. "No matter what the grand jury decides, I don't want my son's death to be in vain. I want it to lead to incredible change, positive change, change that makes the St. Louis region better for everyone."