The U.S. Embassy in Uganda said it had been warned of a “specific threat” of attack to the country’s main airport Thursday and that travelers therefore “may want to review their plans.”

The warning was one of several recent alarms in restive East Africa, where governments have sought to counter threats, particularly those by the al-Shabab militant movement based in Somalia.

The embassy did not specify what the threat entailed, but said it had “received information from the Uganda Police Force that, according to intelligence sources, “there is a specific threat to Entebbe International Airport,” which serves the capital, Kampala.

The warning, in a statement on the embassy’s website, said the attack could take place between 9 p.m. and 11 p.m. Thursday.

“U.S. Embassy Kampala wishes to remind U.S. citizens of the continued threat of potential terrorist attacks in the country,” the statement said. “The targets for these attacks could include hotels, restaurants, nightclubs, shopping malls, diplomatic missions, transportation hubs, religious institutions, government offices, or public transportation.”

The embassy’s warning followed a separate alert Wednesday by Uganda’s Civil Aviation Authority, Reuters reported.

The alert also coincided with alarms about flights from Europe and the Middle East to the United States because of concerns that militants may have developed explosives undetectable by conventional airport security devices.

Uganda has troops in Somalia fighting al-Shabab as part of an African Union force and has been on alert in case that involvement draws reprisals. In 2010, al-Shabab claimed responsibility for attacks on bars in Uganda where people had gathered to watch World Cup soccer games. Scores of people were killed.

Elsewhere in the region, Kenya has blamed the Somali-based group for attacks including last year’s bloody assault on the Westgate mall in Nairobi.

According to Agence France-Presse, a Ugandan army spokesman, Paddy Ankunda, said Thursday that troops had been deployed at the airport and in the capital.

“People must be vigilant in the face of this threat, report any suspicious individuals seen in their areas,” he said, calling on people to “stay calm and alert.”