Costa Rican police arrested seven people Wednesday in connection with the murder of an environmentalist who was killed protecting sea turtle nesting areas from poachers.

The arrests were made in a series of raids in El Limon, a Caribbean port 100 kilometers (60 miles) northeast of San Jose, judicial police spokeswoman Marisel Rodriguez said.

Jairo Mora, 26, was shot dead on May 31, after being intercepted on Moin beach by a group of hooded men.

Mora was accompanied by four women -- three Americans and a Spaniard -- who were walking the beach with him to keep poachers from robbing turtle eggs.

The women were separated from Mora and locked in an abandoned building, while the environmentalist was taken away to his death.

His nude, bound body was found face down in the sand with a gunshot wound to the chest.

Police said that in Wednesday's raids they recovered some bags that belonged to the women, and that some of the arrested had records for assault and violations of environmental laws.

Mora worked on a conservation project sponsored by local environmental group Eco Paradero and international organization Widecast.