(NAIROBI, Kenya) -- More than 20 people were killed at an upscale shopping mall in Nairobi after at least one gunman opened fire Saturday afternoon. The shooting appears to be a terrorist attack. Police remain at the scene, says the Daily Telegraph, and the shooter or shooters are still believed to be inside the mall. Security services say that people were still being held hostage inside the mall.
The mall is one of the newest and most popular malls in Nairobi, and has previously been the target of terrorist threats.
It is unclear how many people were injured in the attack. The Kenyan Red Cross is reporting 22 people were killed.
The U.S. Embassy in Nairobi has advised Americans to stay home and avoid public places. The U.S. State Department is looking into reports of Americans injured in the attack.
A self-proclaimed spokesperson for Somali group al-Shabab tweeted indicating the group's involvement.
"The Kenyan government, however, turned a deaf ear to our repeated warnings and continued to massacre innocent Muslims in Somalia #Westgate," @HSM_Press tweeted.
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