One bomber was killed after a suicide car bomb denoted by suspected Taliban insurgents on Monday at a US-operated military base in Afghanistan's southeastern Khost city. A spokesman for the US military in Afghanistan confirmed the attack, AFP reported.

The bomber died on the spot. A child injured in the attack has been hospitalized, but there have been no further detailed reports on casualties, according to Afghanistan's Khaama Press. The blast site has been cordoned off.

The attack occurred after US Defense Secretary Jim Mattis arrived in the country on Monday for an unannounced visit. He is expected to meet Afghan officials and US troops in Kabul.

Earlier on Monday, Afghan President Ashraf Ghani accepted the resignation of the defense minister and army chief of staff after more than 140 soldiers were killed in a Taliban attack on an army base last week in Mazar-i-Sharif.

‍US defense secretary makes surprise visit to Afghanistan‍

‍Afghan defense minister, army chief of staff resign over deadly attack‍