Bulgaria said on Saturday it was days away from sending coronavirus patients abroad as a vicious fourth wave overwhelms its health system and forces neighbouring Romania to ramp up restrictions.

Health Minister Stoycho Katsarov told the Nova TV channel that if the current rate of infections was not stemmed in 10 to 15 days there would be "enormous problems".

"Our capacity in terms of staff and ventilators has been practically exhausted, we will have to seek help from abroad," he said.

"Talks are underway with the EU to transfer patients to other countries if it comes to that."

Katsarov has also warned a lockdown cannot be ruled out.

Despite the introduction of a pass for places such as restaurants and shopping centres, experts say the current wave could lead to infections leaping from around 5,000 a day to 9,000 a day in two weeks in the country of 6.9 million.

Bulgaria has suffered one of the world's highest death rates with the total standing at almost 23,000 people.

Over the past year Bulgaria has faced a protracted political crisis alongside the pandemic, with the third parliamentary election this year due to take place next month.

Vaccination surges

Bulgaria and neighbouring Romania together have the lowest vaccination rates in the EU, with low takeup blamed on the widespread circulation of conspiracy theories and mistrust of the authorities.

Only 24 percent of Bulgarians have been fully vaccinated while in Romania the figure is barely 33 percent.

Romania is bringing in harsher measures this Monday to try to bring infections under control.

The country of just over 19 million has now recorded in excess of 1.5 million cases, with more than 15,000 new infections recorded on Saturday.

More than 44,000 people in Romania have died after contracting the virus and the government has had to transfer around 30 patients to neighbouring Hungary as its threadbare healthcare system buckles.

As of Monday, will be compulsory across the country and gatherings such as weddings and conferences will be banned for 30 days.

Spaces such as gyms, shopping centres and restaurants will require a health pass for entry, while unvaccinated people will face a 10 pm curfew.

The one-week school holiday due to begin on Monday has also been extended for seven days.

Controversially, church services have been exempted from the need for attendees to provide proof of vaccination or recovery.

There are signs that the introduction of health passes in both countries has pushed some to get the jab.

The Romanian government announced on Friday that 130,000 Romanians had headed to vaccination centres in the past 24 hours, including a record 86,000 people getting their first shot.

Vaccination centres in Bulgaria also reported a surge in takeup after the introduction of the health pass was announced on Tuesday, with three times as many people getting jabbed on Friday as compared with the previous week.