A Washington newspaper reports the United States has sharply escalated its counter-terrorism operations at a military base in the East African nation of Djibouti.

The Washington Post says unmanned drones on missions over Somalia and Yemen take off or land at the base an average of 16 times per day.

It says about 300 personnel plan raids and coordinate the flights from inside a high-security compound at the base, Camp Lemmonier.

The U.S. was previously known to operate drones from airports in Ethiopia and the Seychelles islands, in addition to Djibouti.

But, the Post says those operations pale compared to the one at Camp Lemmonier. The paper calls Lemmonier the centerpiece of an expanding U.S. network of drone and surveillance bases in Africa, created to combat terrorist groups across the continent.

The U.S. has used drones to attack targets associated with al-Qaida in Yemen and the militant group al-Shabab in Somalia, in addition to terrorist suspects in several other countries.

The Post says it based its report on unclassified military records it obtained, including construction blueprints, drone accident reports and internal planning memos.

It says the Defense Department is planning to spend $1.4 billion to expand its facilities at the Djibouti base.

The paper says the base has also become home to a squadron of F-15 fighter jets. It says two former U.S. defense officials, speaking on condition of anonymity, said the jets are flying combat missions over Yemen in the war against al-Qaida.

The Post says the U.S. military's Africa Command confirmed the warplanes' presence but declined to answer questions about their mission.