The US military has quietly upped the tempo of its operations in Somalia, conducting a growing number of drone strikes against Al-Qaeda affiliated Shabaab group and other militants. Since the start of the year, America has carried out 28 drone strikes in the Horn of Africa nation, with 15 of these coming since September 1, the militarys Africa Command (AFRICOM) said, according to Agence France Presse. Thats a big increase from last year. According to the London-based Bureau of Investigative Journalism, which maintains a tally of US operations in Somalia and elsewhere, there were 15 anti-Shabaab air strikes in the whole of 2016. The surge in activity comes as the US watches for an influx of fighters from ISIS, which has lost almost all its territory in Iraq and Syria. The US conducted a pair of drone strikes against ISIS in Somalia on November 3, the first time it has hit the terrorist group there. Though the Pentagon has provided few details about the strikes, spokesman Colonel Rob Manning said this week that US forces had killed 40 Shabaab and ISIS militants in a series of five strikes on Somalia between November 9 and 12. On Wednesday, AFRICOM announced a sixth strike that killed "several" Shabaab militants 60 miles (97 kilometers) northwest of the capital, Mogadishu. The surge in activity comes after President Donald Trump in March loosened constraints on the US military in Somalia, allowing commanders to take action against suspected terrorists when they judge it is needed, without seeking specific White House approval. Pentagon spokesman and Joint Staff Director Lieutenant General Kenneth McKenzie told reporters Thursday that he didnt necessarily think there was a ramping-up of operations, but said the "density of targets" meant more strikes had been possible. "Theres no particular rhythm to it, except that as (targets) become available and as were able to process them and vet them, we strike," he said.