The U.S. military has expanded its renewed air war in Afghanistan, striking targets in northeastern Afghanistan affiliated with the Taliban and another small militant group that is known for its roots in China, U.S. military officials said Tuesday.

The bombing has been carried out over the past four days in Badakhshan province’s Wurduj district, said Navy Capt. Tom Gresback, a U.S. military spokesman in Kabul. The strikes targeted training camps, “preventing the planning and rehearsal of terrorist acts near the Afghan border with China and Tajikistan,” U.S. military officials said in a news release.

Gresback said that in addition to the Taliban, the U.S.-led military coalition in Afghanistan has targeted the East Turkestan Islamic Movement in the operation. The Islamist separatist group was formed in northwestern China’s Xinjiang region and cited by the United Nations in 2002 and is believed to be affiliated with al-Qaeda.

The ETIM is more commonly referred to now as the Turkistan Islamic Party, said Thomas Joscelyn, a senior editor of the Long War Journal, which tracks militant groups. The group has members in both Afghanistan and Syria, and is interested in attacks on China, he said. The movement seeks an independent state that would stretch across several countries in southwestern Asia, including Uzbekistan, Kyrgystan and Kazakhstan, Pakistan and Afghanistan, according to the Council on Foreign Relations.

“U.S. and Afghan National Defense and Security Forces will pursue and destroy all terrorist elements that seek to undermine Afghanistan or use its territory as a safe haven,” Gresback said in an email. “ETIM was under the false pretense they can have sanctuary in Northeastern Afghanistan for their training camps. If any terrorist organization believes they can use Northern Afghanistan, or any part of Afghanistan,  as a base to advance their cause to other countries, they are mistaken.”

The bombing has involved 24 precision-guided munitions dropped from a B-52 on Taliban positions. That set a record for the largest number of guided weapons dropped from a B-52 and followed the Air Force installing rotary launchers on the bombers over the past few years, the news release said.

Badakhshan is a sparsely populated area that sits in the Hindu Kush and Pamir mountain ranges. The U.S.-led military coalition in Afghanistan has rarely focused its efforts there, though it has occasionally targeted the Taliban and the Haqqani network, a Pakistan-based terrorist group affiliated with it, in the province.

The strikes are the latest in a series that began after President Trump’s new strategy in Afghanistan was announced in August. The plan calls for bumping up the number of U.S. troops there to as many as 15,000 and giving new authority to U.S. commanders to strike the Taliban in an effort to force the militant group to eventually negotiate a truce with the Afghan government. Trump and Defense Secretary Jim Mattis have declined to provide a timetable for the plan, saying that doing so would take away leverage.

Army Gen. John W. Nicholson Jr., the senior U.S. military commander in Afghanistan, said in the release that there will be no haven in Afghanistan for any terrorist group and that the Taliban has “nowhere to hide.” The Taliban actually is not on the State Department’s list of designated terrorist groups, though it often has carried out attacks on U.S. troops and other Americans.

“The Taliban cannot win on the battlefield, therefore they inflict harm and suffering on innocent civilians,” Nicholson said. “All they can do is kill innocent people and destroy what other people have built.”

The B-52s are not based in Afghanistan but carry out operations there from Al Udeid air base in Qatar. Other strike aircraft are based in Afghanistan, including F-16 jets flown from Bagram air base and A-10 attack jets that recently arrived at Kandahar Airfield in the southern part of the country.

The Air Force significantly stepped up its bombing campaign in Afghanistan last year, dropping 4,361 bombs, compared with 1,337 in 2016, according to data released by the service. Other bombing was carried out by the Navy and Marine Corps, but those statistics were not immediately available.