About 750 interior ministry officers will guard the state ceremony for the remains of Tsar Samuil in Sofia on October 3, says chief inspector Ivan Georgiev, who heads the mass events unit at Sofia's police directorate. Around 550 come from the Sofia directorate, with another 200 or so sent in from the national gendarmerie, special police forces and the counter-terrorism and special operations directorate.

Two zones will be set up around the event on Tsar Osvoboditel Boulevard. The first, where the official part takes place, can only be entered through a police checkpoint. In the second, people will go through spot checks at certain points before being let in. Glass bottles, metal batons and anything else that could endanger people's lives or health are banned, and police will decide who gets checked.

Screening points will be set up at Nezavisimost Square, the garden by the Ivan Vazov National Theatre, near the Grand Hotel Sofia, on Benkovski Street and Tsar Osvoboditel Boulevard, by the Alexander Nevsky Cathedral, on Moskovska Street, and at the Tsar Osvoboditel monument.

Preparations begin around 4am, when cars will be cleared from the car park at Knyaz Alexander I Square, from Knyaz Alexander I Street between Tsar Osvoboditel Boulevard and Gurko Street, from the area in front of the Archaeological Museum, from around the Alexander Nevsky Cathedral, from the stretch of Moskovska Street between Malko Tarnovo Street and Dunav Street, and from Nikolai Ghiaurov Square.

Traffic on Tsar Osvoboditel Boulevard between Dunav Street and Rakovski Street will start closing in stages from around 10am. Around noon, depending on how the ceremony goes and when the plane lands, restrictions will kick in along the route from Sofia Airport via Mimi Balkanska Street, Brussels Boulevard, Tsarigradsko Shose and Tsar Osvoboditel Boulevard to Rakovski Street. Georgiev said the closures will last only as long as strictly needed, so as not to make traffic worse.

The ceremony is expected to end around 1:20-1:25pm. A procession will then move along Tsar Osvoboditel Boulevard, turn left onto Rakovski Street, right onto Oborishte Street and left onto Paris Street to the entrance of St Sofia Church. People will walk on the pavements rather than the road, though Georgiev said that if crowds are large, even the pavements could get congested. Traffic is expected to reopen around 1:30pm, except on the stretch of Tsar Osvoboditel between Rakovski Street and Dondukov Boulevard.

Once the remains are laid to rest, St Sofia Church will stay under heightened guard for a set period. After that, officials will decide how to keep watching over it using technical equipment.

President Rumen Radev announced the agreement with Greece on returning the remains on Tuesday and invited people to the welcoming ceremony at 12:30pm at Knyaz Alexander I Square. The remains will be formally handed over to Bulgaria in Thessaloniki on October 3 and flown to Sofia aboard a Spartan military transport plane, before being placed in a special sarcophagus inside the St Sofia basilica.