A coalition of environmental groups is asking a federal judge in San Francisco to halt work on the highway bridges over the Petaluma River while the court considers their lawsuits contending that the work endangers federally-protected migratory birds.

The groups filed for an injunction late Tuesday, but the first available hearing date before Judge Jon S. Tigar is not until July 11.

Animal Legal Defense Fund attorney Danny Lutz said the groups will ask the judge to hear the request sooner.

The groups sued earlier this month saying that netting designed to keep migratory cliff swallows away from the $130 million bridge project, which will add HOV lanes to Highway 101, ended up entangling and killing dozens of birds. They are asking the court to force the agency to do more extensive environmental review before resuming work.

Caltrans declines to comment on the lawsuit, but had previously said that the problem with the netting was inadvertent and was corrected quickly. The environmental groups say the agency did improve the situation, but that birds continue to get caught in the netting.