BUCHAREST, Feb 14 (Reuters) - Romania confirmed on Tuesday a strain of avian flu had infected poultry found dead on Monday in a village near the Black Sea port of Constanta and detected new suspect cases on a farm close to the Bulgarian border.

Bird flu has been discovered in 31 villages across the country since the virus was first detected in October in the Danube delta, Europe´s largest wetlands and a major migratory route for wild birds. Romania has not reported any human cases.

"Tests made on samples from two dead hens found in the village of Topraisar confirm the presence of bird flu," head of the Animal Health and Diagnosis Institute Nicolae Stefan told Reuters.

"We will take regular measures to quarantine the village and cull all domestic birds there," Stefan said.

He said the samples would be sent to a British laboratory in Weybridge to find out whether the strain was the deadly H5N1. Romania is not able to test for H5N1.

The village of Topraisar lies 20 km (12 miles) south-west of Romania´s largest port of Constanta.

Authorities also said suspicious poultry deaths were recorded in the village of Vlahi, in Constanta county, 25 km north of the border with Bulgaria, which has reported its first avian flu cases over the past few days.

"Preliminary tests made on several hens from a small farmyard in the village of Vlahi showed suspicion for the bird flu virus," Stefan said.

He said all poultry in the farmyard were killed and that around 2,500 domestic birds in the village would be culled if further tests confirm the virus.