FORT WORTH (CBSDFW.COM) – In the “interest of public safety,” Fort Worth Mayor Betsy Price has executed a declaration of emergency and implemented an 8 p.m. city-wide curfew for the next 72 hours.

“Unfortunately, there are also those among us who have displayed blatant disregard for the welfare of others,” Price told reporters.

Price tweeted the announcement Monday morning.

Her decision comes after a night of peaceful protests, which turned aggressive overnight in the West 7th area of Fort Worth.

“This decision was not made easily, but it comes at the recommendation of our partners, and the Chief of Police. We put our heads together and decided it was right for our community,” said Price.

Protesters blocked traffic on the West 7th Street bridge, forcing police to use tear gas to disperse the crowd. It was the first sight of protesters blocking off the bridge over the Trinity River since marches began all over the country following last Monday’s in-custody death of George Floyd in Minneapolis.

“After dark officers started being attacked with what we first thought were water bottles, but we’ve since come to believe those bottles filled with bleach because of the empty bleach containers we found on the bridge,” said Fort Worth Police Chief Ed Kraus. “That followed with frozen water bottles and rocks being hurled at the officers.”

Fireworks were also lit in the area and thrown toward the officers. At that point, officers, a SWAT unit, deployed smoke — which is not gas — smoke and flashbangs, according to Kraus.

It was the first time gas was used on a crowd in the city in 30 years.

“That was preceded by three requests over the PA system for the crowd to disperse with warnings of what we were about to do. Some of the people listened and left, others did not heed those warnings that were spaced out several minutes apart. We made sure that the crowd had an avenue of escape if they chose to leave they could just go back eastbound across the bridge, and they would not be impeded.”

The chief also mentioned protesters who remained peaceful.

“There were some people there who intended to peacefully protest. And thankfully they made the decision to leave when they were warned,” he said.

Kraus said three officers were injured. One was hit in the elbow by an ice ball, another broke his leg and another officer twisted his knee.

Overnight some businesses were vandalized and looted, too.

Of the 50 people arrested, half of them were not residents of Fort Worth.

(credit: CBS 11 News)

Price also announced that Tuesday’s city council meeting was moved. The 7 p.m. meeting is now scheduled for 3 p.m. on Thursday to ensure they can hear from all residents.