Federal and Baltimore authorities on Thursday announced a slew of arrests, indictments and seizures in four separate federal cases.

Joined by officials from a number of federal agencies, local prosecutors and city Police Commissioner Michael Harrison, U.S. Attorney Robert K. Hur announced that his office's latest efforts led to 90 indictments and the seizure of kilograms of opioids and 51 guns.

"While it takes only the blink of an eye to take a life with a gun, it takes much longer to gather the evidence necessary to bring the people responsible to justice," Hur said.

In one set of 21 indictments issued last month, Hur said, investigators seized 20 guns and some $200,000 from a northwest Baltimore gang that allegedly dealt heroin, crack cocaine, powered cocaine, fentanyl and marijuana. He said gang members carried out acts of violence including a January shootout.

In another case, 25 people were indicted on 35 counts related to an alleged drug ring in east Baltimore. The suspects allegedly distributed heroin, fentanyl, cocaine and crack cocaine to individuals, and bulk quantities to other dealers. Ten also face firearms charges. Investigators seized nine guns, more than 15 kg of cocaine, around 4.5 grams of heroin and 479 grams of fentanyl. That is enough to kill more than 200,000 people, prosecutors said. Investigators also seized more than $472,000 in cash and jewelry and vehicles worth more than $466,000.

This week, city and state leaders and Democrats nationwide are condemning remarks made by President Donald Trump denigrating Baltimore and Rep. Elijah Cummings. Trump in tweets over the weekend described Cummings' district as a "disgusting, rat and rodent infested mess" where "no human being would want to live." Hur said he is not sure if Trump is aware of the latest indictments, but emphasized the importance of partnerships between federal agencies and state and local authorities. 

Harrison told reporters the president's tweets have only made authorities "more resolved and stronger willed."

"Trust me when I tell you you're making a difference," Harrison told federal officials at the press conference. "And I think our coordinated message to the Baltimore community is: we're removing drugs from the streets, we're removing guns from the streets and we're removing bad actors from the streets of Baltimore."

Hur said his office is planning a community resource at Union Baptist Church, the site of Thursday's press conference.

"Our goal is a safer city with less vioplence, fewer guns, fewer victims and fewer grieving families," Hur said. "I love the city of Baltimore and I am proud to work with the men and women of Baltimore who work tirelessly every day to make our city safer."