Bahrain International Air Show is organised by the Ministry of Transportation and telecommunications and Royal Bahraini Air Force.
80 per cent of 10,000 have legally joined a new employer, while 20 per cent preferred to return to their home countries.
Two parents and their child were also hurt in the blast in Karanah suburb, the Information Minister said.
"One policeman killed in the terrorist blast in Karana village," it said on its Twitter account, giving no further details.
The Bahrain Petroleum Company (Bapco) has recently sponsored the Ministry of Interior's recent anti-drug national campaign.
He was held on August 18 after returning from a trip to collect funds in Iran.
The collection of 100 luxury apartments at the Lagoona Beach Luxury Resort & Spa Residences are the first of its kind in Bahrain.