Golf: Rookie Bjork and Jamieson share lead in Tshwane Open

PRETORIA, March 3 (Reuters) - Alexander Bjork of Sweden and Scott Jamieson of Scotland shared the halfway lead on 10 under par at the Tshwane Open as a thunderstorm disrupted the second round at Pretoria County Club on Friday. Tour rookie Bjork, who was in a three-way tie for the lead after the first round, kept up his form with a four-under-par 67 which included two bogeys.