KABUL, Afghanistan — No one will ever know what went through the mind of Afghan Police Lt. Sayed Basam Pacha in those moments when he came face to face with a man he suspected of being a suicide bomber on Thursday afternoon, but whatever it was, he did not hesitate to act.

At his back was a crowd of civilians, many of them dignitaries, leaving the hall he was guarding. Around him were officers from the police company he commanded. The suspect had just approached their heavily guarded gate, the only way in or out of the compound around the hall.

Broad-shouldered and heavily muscled, Lieutenant Pacha shouted at the suspect to halt, but instead the man started running. The officer stopped him, throwing his arms around him in a bear hug.

A second later the bomber detonated the explosive vest hidden under his coat. Fourteen people, including Lieutenant Pacha and seven other police officers as well as six civilians, were killed; 18 others were wounded, seven police and 11 civilians, said Basir Mujahed, a police spokesman.