HOUSTON, July 5 (Xinhua) -- A tragic burst of gun violence in multiple U.S. cities over the Independence Day weekend has claimed more than a dozen lives.

Four people were killed and seven others were injured in a shooting at a Fourth of July celebration party shortly before Tuesday midnight in Shreveport, Louisiana, authorities said on Wednesday.

At least one gunman opened fire at a gathering of about 100 people in the community event, that has reportedly taken place for more than a decade, police said.

Hours after U.S. President Joe Biden lamented the new "wave of tragic and senseless shootings" on Tuesday, nine people, including two minors, were injured shortly before 1 a.m. Wednesday when a shooter from a vehicle opened fire at people attending a Fourth of July celebration in Washington, D.C., Metropolitan Police said.

In downtown Fort Worth, Texas, at least three people were killed and eight others were injured in a shooting just before midnight on Monday at a Fourth of July celebration gathering.

Philadelphia also confronted a mass shooting on Monday night, with four people killed and four others injured.

In another mass shooting incident early Sunday, two people were killed and 28 others injured in Baltimore, the most populous city in the state of Maryland.

Shootings were also reported in some other cities over the weekend, including Lansing, Michigan, and Wichita, Kansas, leaving at least 10 people injured, local media reported.

Over the past decade, the United States has encountered five mass shootings each Independence Day on average -- more than on any other day of the year, USA Today reported last week.

Some Americans said they were nervous about attending big public events this year for the Fourth of July, given the number of mass shootings around the country in recent years, according to a New York Times report.