Rescuers outside the sports centre, which collapsed in high winds. (Manu Fernandez/Associated Press)Four children were killed and several others injured when a sports centre collapsed near Barcelona during a powerful wind and rain storm Saturday.

Officials said 16 children were hurt as the metal roof and part of a wall collapsed. Nine were treated in hospital and later released.

Those who died were all boys, aged 9 to 12, officials said.

Three of the children died at the scene while the fourth died at Sant Joan de Deu hospital, a regional government official said on condition of anonymity.

Three other children were in serious condition Saturday and the other injured people, including two adult baseball coaches, were either lightly injured or already released from hospital, the official said.

Accident investigators took photographs of the scene on Saturday and performed tests to determine the cause of the collapse.

Witnesses say the children were at the facility in the town of Sant Boi de Llobregat to play baseball and had sought shelter under a viewing stand during a storm that brought heavy rain and winds gusting to 160 km/h.

The structure came down around 11:30 a.m. local time, officials said.

"The building itself was pretty new. It was rebuilt 25 years ago and, looking at it, basically it seems one part has totally collapsed," freelance journalist Graham Keeley told CBC News.

Elsewhere, a woman died when a wall fell on her in Barcelona and a traffic officer was killed by a falling tree in the northern Spanish province of Galicia.

The storm system has swept through parts of southwestern France, where the storm has knocked out electrical power to about a million homes.

A driver was killed and his passenger injured near Mont-de-Marsan when a tree fell on their van.

The storm has also led to the closure of several rail lines, as well as airports in Bordeaux, Pau and Biarritz, and Toulouse.