Two Kenyan athletes have accepted provisional bans after testing positive for banned substances.

400 metre runner Joyce Zakary and 400 metre hurdler Koki Manunga were the subject of "targeted tests" by the the International Association of Athletics Federations in Beijing.

Zakary set a national record of 50.71 seconds in the 400 metre heats on Monday, but did not apear for her scheduled semi-final yesterday.

Manunga finished sixth in her heat of the 400 metre hurdles after recording a time of 58.96.