KABUL, Afghanistan — A suicide bomber who walked into the crowded center of Khost in eastern Afghanistan on Monday morning as foreign and Afghan soldiers conducted a joint foot patrol killed three international service members and 16 Afghan police officers and civilians, witnesses and hospital officials said.

A spokesman for the American-led coalition forces here said that three international service members and a civilian translator died in a blast in eastern Afghanistan, but he did not specify the location, in accordance with military rules barring the release of information about deaths until the next of kin are informed.

The Taliban claimed responsibility for the attack. “A foreign and Afghan force joint convoy was targeted this morning around 9 a.m. in the vicinity of the Khost governor’s office, while the soldiers were dismounted in the area,” the Taliban said in a statement to the news media. “The attack was carried out with a suicide vest worn by one of our hero mujahid, named Shoiab Kunduzi.”

It was the fourth suicide bombing in Khost Province in the last five months and the third in which the targets were in Khost City, the provincial capital, local officials said. Among the others were an attack near the gates of Camp Salerno, the major American base in the area, which is about five miles from the provincial capital, and an attack at a military checkpoint in the city.