GAZA CITY, Gaza Strip — A pro-Hamas bloc has won control of a union representing Palestinians working for a UN agency in Gaza.

The bloc won 25 out of 27 union seats in a late Monday vote among 10,000 staffers with the U.N. Relief and Works Agency.

The development underscores Hamas' influence among Gaza's professionals even though it has been criticized lately for ignoring the needs of the poor.

It may also increase tensions between the U.N. agency and Hamas. The U.N. has tried to curb Hamas' power over the union in the past. A U.N. spokesman declined to comment.

Hamas has ruled Gaza since seizing power in 2007. It sees the U.N. as a rival to its dominance, because the agency runs schools, clinics and provides food to many in the coastal territory.