Red flagpublished at 14:19

14:19

A short-lived restart as the red flags are waved with Marcus Ericsson's Sauber in the wall at Pouhon.

"I hit the wall, sorry," he says.

OK, the circuit is clear again and everyone quickly heads back out on to the circuit with 13 minutes left. 

Lewis Hamilton, for now, does not head out. Mercedes perhaps keen to establish what happened to Nico Rosberg before sending the Briton back out.

A bit more from Nico Rosberg about that incident: "I think the tyre broke on the rear but I am not sure. 

"Let us wait and see but I was at maximum speed so that is not good. There was no debris. I had it happen before in testing."

"That was definitely not fun," says Nico Rosberg calmly as he walks back to the Mercedes garage.

King of the understatement right there.

Nico Rosberg is up and out of his car, which is then lifted up on to the recovery truck. The German waves to the crowd, assuring them he is a-ok. 

Breathe easy.

James Allen
BBC Radio 5 live F1 commentator

"That was a scary, heart-in the mouth moment for Nico Rosberg. I hope his wife was not watching back home."

Allan McNish
BBC Radio 5 live analyst

"He spun round and thankfully there was a huge amount of run-off area but that was a heart stopping moment for Nico Rosberg."

Wow! Dramatic scenes as Nico Rosberg's right-rear explodes approaching Blanchimont. The Mercedes spins, but thankfully manages to avoid the barrier. Rosberg is OK.

Red flagpublished at 14:04

14:04

Spin for Nico Rosberg and the session is stopped...

Nico Rosberg was lapping in the mid-1:54s but his times are dropping off a bit now, his latest a 1:56.765.

Jennie Gow
BBC Radio 5 live pit-lane reporter

"I am stood by the Williams garage. They have been doing some setup changes to Felipe Massa car and both now have the same rear-wing set up."

Interesting to see the Williams pair of Valtteri Bottas and Felipe Massa way down the timesheet - 14th and 16th respectively. Jennie Gow has popped over to their garage to see what's going on...

Heading into the final 30 minutes of the session and teams are either preparing for, or have already started, their race simulation runs. 

 "Target lap time is low 1:54s," comes the message from the Mercedes pitwall.

Sauber have called Marcus Ericsson and Felipe Nasr in after their low fuel runs. Pastor Maldonado is also told to box because of a problem with the front left brake caliper on his Lotus.

Nico Rosberg's 1:49.385 is still the benchmark, will someone beat Lewis Hamilton's timesheet topping 1:49.189 from 2014?

Romain Grosjean goes fourth fastest, putting him behind Kimi Raikkonen, Lewis Hamilton and Nico Rosberg. 

Two Saubers have the fifth and sixth fastest times, with Marcus Ericsson ahead of team-mate Felipe Nasr.

Pastor Maldonado, meanwhile, has been out and 1:53.981 and completed a time lap in the now repaired Lotus. He doesn't look entirely comfortable, though, running wide at Turn 15, a corner that also causes Max Verstappen a little bit of bother soon after.