ROME (Reuters) - A German humanitarian rescue ship went to the aid of a vessel run by a group of anti-immigration activists on Friday, but were told when they arrived that their help was not needed.

The Sea-Eye charity’s founder Michael Buschheuer said the Italian coastguard had asked his ship to set course for the activists’ C-Star vessel because it was in distress.

The Identitarian group running C-star, however, denied on Twitter that the vessel was in distress but said it had alerted other vessels because its main engine had stopped due to “a minor technical problem”.

Once the Sea-Eye arrived, the C-Star refused assistance, Sea-Eye’s Buschheuer told Reuters by telephone.

“We had radio contact. They said they don’t need or want our help,” Buschheuer said.

Supporters of the Identitarian movement have vowed to “defend” Europe from a migrant “invasion” from Africa.

The “Defend Europe” activists of Identitarian have struggled to get their mission underway. The C-Star was held up in Egypt and Cyprus, and later refused access to Tunisian ports.

In Cyprus, the crew of the C-Star was stopped on suspicion of smuggling Sri Lankan men to Europe, and then later released.

Calling itself a “patriotic NGO”, the group is tapping into growing unease in Europe about immigration from North Africa that has brought some 600,000 impoverished migrants and refugees to Italy in less than four years.

In that time, more than 13,000 have died trying to make the crossing. Since 2014, charity groups have been operating rescue ships that have pulled tens of thousands of migrants from overcrowded and unsafe boats to safety.