Natalie DiBlasio

USA TODAY

Americans in Uganda are being advised by the U.S. government to stay at home or move to a safe location as Ugandan authorities attempt to foil a possible terror attack.

Ugandan authorities reported the discovery of an an-Shabab terrorist cell in Kampala, Uganda, on Saturday morning.

"We are continuing our engagement with Ugandan authorities as we seek to assess the scope of the disrupted al-Shabab terrorist plot and whether there are members of the cell still at large," the U.S. Embassy in Uganda wrote in a message on its website. "As a cautionary measure, and to give authorities time to put their heightened security measures in place, we urge all U.S. citizens to continue to shelter in place through this evening."

Last week, al-Shabab, an Islamist extremist group linked to al-Qaeda, vowed to revenge the killing of its former leader, Ahmed Abdi Godane, after the U.S. confirmed it took him out in an airstrike.

Four years ago, the group bombed two World Cup viewing locations in Kampala, killing more than 70 people. Last year, it claimed responsibility for the attack on Westgate Mall in Nairobi, Kenya, that killed 67 people.

Kenya, Uganda, Ethiopia, Djibouti and Sierra Leone have deployed troops to Somalia, where al-Shabab is based, as part of the African Union joint force to bolster the country's weak government.

Contributing: The Associated Press