Updated

Environmental activists headed to the U.N. climate conference in neighboring Peru say Ecuadorean police stopped and harassed them six times before seizing their bus.

Delegation member Ana Romero says she believes the bus carrying 15 members of the Yasunidos group was repeatedly stopped Tuesday because President Rafael Correa's government doesn't want them to protest plans to drill for oil in Yasuni, an Amazon basin nature reserve with some of the world's greatest biodiversity.

The group tried to force a referendum to prevent drilling, but an electoral council packed with Correa loyalists said it failed to gather the required signatures.

Romero says the bus was seized Tuesday evening and the group is seeking donations for transportation to continue on to Lima.

Police did not immediately respond to a request for comment.