At least one person was killed and 26 others were injured in an attack by militants on a university in Kabul on Wednesday, health officials said.
The person who died was a guard, according to the officials. Among the injured were four women, Afghan public health ministry advisors Hedayatullah Stanakzai and Wahidullah Majroh said. The women were admitted to hospital after the attack, which unleashed panic on the campus.
Ahmad Samim, an associate professor at the university, said he begged for his life. "Don't kill me I am very innocent," he said on Twitter. The professor later said he was safe and away from the university.
Security forces were surrounding the area.
"We are inside the university conducting search and clearance," said General Abdul Rahman Rahman, the police chief of Kabul.
The security forces were working slowly and very carefully because there was no electricity within the university, according to a police criminal investigation official, who requested to remain anonymous.
US State Department spokeswoman Elizabeth Trudeau said there were "small numbers" of NATO advisers who were assisting their Afghan counterparts. The advisers are not taking a combat role but are advising Afghan counterparts, she said.
The United States condemned the attack "in the strongest possible terms," she said. "An attack on a university is an attack on the future of Afghanistan."
Government Chief Executive Abdullah Abdullah condemned what he termed the cowardly attack on the university. "Attacking schools, universities & innocent people is a war crime. We can not bear it!" he wrote on Twitter.
No group has so far claimed responsibility for the attack.
Earlier this month one US and one Australian professor working at the American University were kidnapped by gunmen.
The American University of Afghanistan has around 1,000 students studying various subjects at the bachelor and master's level.