The American embassy in Somalia has warned that a significant data breach in the country's electronic visa system may have compromised personal information of tens of thousands of applicants, including U.S. citizens.

It said had received credible reports that "unidentified hackers" had penetrated the Somali government's e-visa platform, potentially compromising data from at least 35,000 people, News.Az reports citing the BBC.

The leaked documents circulating online include names, photos, dates of birth, marital status, home addresses and email contacts, according to a US embassy statement issued on Thursday.

"This data breach is ongoing and could expose any personal data you enter into the system," the UK has also warned travellers.

"Consider the risks before applying for an e-visa required for travel to Somalia."

Somali authorities have not commented on the breach. But the government has shifted its visa service from evisa.gov.so to etas.gov.so, without providing an official explanation.

"While Embassy Mogadishu is unable to confirm whether an individual's data is part of the breach, individuals who have applied for a Somali e-visa may be affected," the US' statement said.

Somalia's new system requires all travellers, including those from the self-declared republic of Somaliland and the semi-autonomous region of Puntland, to apply for entry visas online.