Police in Tokyo are increasing security across the capital before the arrival of foreign dignitaries for the state funeral of former Prime Minister Abe Shinzo.

The funeral is set to take place on Tuesday at Nippon Budokan in central Tokyo. Abe was shot and killed on July 8 while giving an election campaign speech.

The Tokyo Metropolitan Police Department has deployed officers to patrol expressways in central Tokyo for suspicious items. On Saturday, police closed some lanes on an expressway near Haneda Airport so officers could conduct checks on foot.

Extra police are also on duty at the airport, with some using sniffer dogs to check for explosives.

Police say they are also ramping up security around embassies and hotels where foreign dignitaries will be staying.