WARRI, Nigeria (AP) — Police in Nigeria say they have arrested the main suspect in apparent serial killings that have sparked protests by women demanding greater security.

Police announced on Twitter that they were questioning the man.

At least eight women have been strangled in hotel rooms in southern Rivers state in the past two months. Women’s rights groups have protested this week in the streets of Port Harcourt in the oil-producing Niger Delta region.

Some activists assert that up to 20 women have been killed in the same manner.

One rights activist, Ibim Semenitari, commends the police for the arrest.