A smoky start for Vettel at Monaco

(GMM) Sebastian Vettel's bid for Monaco victory suffered a smoky setback, as practice action kicked off in the sunny Principality on Thursday morning.

The German had completed 16 laps of the famous street layout when the Renault engine at the rear of his Red Bull let out a terminal stream of blue smoke.

He was able to return to the pits, but remained there for the balance of the 90-minute session as his mechanics set to work on replacing the damaged V8 before action resumes this afternoon.

Teammate Mark Webber's practice was also interrupted when he returned to the pits with a vibration at the rear of his RB5.

Rubens Barrichello topped the session, a few tenths ahead of Ferrari's Felipe Massa and the two McLarens.

Championship leader Jenson Button was eighth quickest, while Robert Kubica slammed the "disastrous" handling of his BMW over the radio before outpacing his teammate Nick Heidfeld – struggling with braking balance – for 16th.

The two Toyotas brought up the rear, 2.5 seconds slower than the leading Brawn.

Results