OLYMPIA, Wash. — Authorities in the Washington state capital of Olympia say they confronted dozens of anti-fracking protesters who had blocked the railroad tracks for more than week.

Olympia police tweeted early Wednesday, warning people to stay away from the area near downtown where Union Pacific Railroad officers confronted 20 to 30 masked protesters.

The crowd dispersed and officials are sweeping the encampments for bombs to clean up the site.

The protesters wanted to block trains carrying ceramic proppants, or fracking sand, and related materials from the Port of Olympia, though railroad companies said there were no shipments scheduled.

The port handles cargo used in the hydraulic fracking extraction process, which extracts oil and gas from rock.

A similar protest last year ended with a dozen people arrested by officers in riot gear.