Panic has gripped Cameroon’s capital, Yaounde, after a confidential letter from the country’s defense minister leaked to social media stating that Boko Haram terrorists had arrived in the city.

The letter from Joseph Beti Assomo to top military officers called for vigilance and additional deployment of troops to ministerial buildings and public areas, such as markets, churches and schools. Military officials said the leak occurred because of lapses in their information system.

In light of the information, some residents have decided to lie low. Businesswoman Belinda Tatah said that when she heard Assomo had urged the military to stop a possible terrorist attack in the capital, she decided to avoid all public places and gatherings.

“You know, if the minister of defense signs a confidential note that there are terrorists in town, any normal human being should be afraid,” Tatah said. “That is why I have decided not to go out, because I am too scared.”

The letter called for increased security at government buildings, army barracks, military hospitals and “crowded” public places. It also called for collaboration between the public and vigilante groups.

Security staff deployed Adrien Njoya, an official at a private security company that filters access to major hotels in Yaounde, said he deployed more of his staff when they were informed of the threats. He said that because the enemy was reportedly at work, he had asked his staff to thoroughly search everyone, even their brothers and sisters who come visiting. He said everyone visiting the hotel should be identified.

Assomo instructed the head of the brigade that protects citizens in the capital to be vigilant and to track suspects immediately. He said intelligence gathering should be intensified immediately and that economic activity, political institutions, diplomatic missions and all foreigners living in Cameroon should be protected. He said terrorism threats in Yaounde were real.

Since their insurgency spilled over into Cameroon three years ago, Boko Haram terrorists have operated only on the country’s northern border with Nigeria. No attacks have been reported in the southern parts of the central African state.

Historically, large open markets, hotels, parks and sporting venues have been targeted by terrorists. Some countries have advised their citizens to maintain restrictions on travel to northern Cameroon, especially travel within 100 kilometers of the border with Nigeria’s Adamawa and Borno states.

Diplomatic missions, including the U.S. Embassy in Yaounde, urged expatriates to exercise caution.