Afghan National Army soldiers march during a ceremony in a military base in the Guzara district of Herat province on Feb. 28. (Hoshang Hashimi/AFP/Getty Images)

Taliban suicide bombers and gunmen assaulted a major army base in Afghanistan’s southern Helmand province early Friday, an attack that left 23 Afghan security personnel and 20 assailants dead as a new round of peace talks between U.S. officials and Taliban delegates in Qatar was underway. 

There were no casualties among the U.S. advisory troops housed in the same base, officials said. But the attack, which began before dawn, lasted until midmorning. Afghan forces battled insurgents, armed with grenade launchers, who had penetrated the sprawling and heavily fortified joint base.

The Taliban immediately asserted responsibility for the attack, which was the group’s second assault on a major military target since peace talks began several months ago. In January, insurgents attacked an Afghan intelligence training compound, killing 26 people. 

A Taliban spokesman, Qari Yousef Ahmadi, said Friday’s assault caused serious damage to a fleet of military helicopters parked inside the base. An aide to the Helmand governor denied that claim.

Army Col. David Butler, a U.S. military spokesman in Kabul, said that U.S. Marines living in another part of the base responded to a smaller attack while Afghans fought off the main one. They “mitigated the threat,” he said in a text message.

The base holds significance in the U.S. military because it was once the co-located home of Camp Leatherneck, a vast base from which thousands of Marines at a time deployed across Helmand during the height of the troop surge in the Obama administration.

Another spokesman, 1st Lt. Ubon Mendie, said in a statement that the American base never came under serious threat. U.S. forces supported the Afghan unit, including with air support, he said.

Both sides in the 17-year conflict have continued aggressive actions as the talks have proceeded. A United Nations report last week said civilian casualties reached a record number of nearly 4,000 last year, owing to a combination of stepped-up U.S. and Afghan airstrikes, insurgent suicide bombings and ground battles in populated areas. 

Taliban and U.S. negotiators in Qatar paused Friday after three days of discussions, which both sides described as positive. Zalmay Khalilzad, the special U.S. envoy for Afghan peace, said earlier this week that he expected the talks to be “significant,” in part because Taliban leaders had sent a key official, Abdul Ghani Baradar, to head their delegation. 

Taliban leaders had said this week’s meetings would focus on their demand for the total withdrawal of U.S. troops from Afghanistan, in return for a Taliban guarantee that Afghan soil would not be used against U.S. or foreign interests.

There have been separate reports this week that President Trump plans to withdraw about 1,000 troops this year. About 14,000 U.S. forces are stationed in the country. 

Dan Lamothe in Washington contributed to this report.