Updated

Europeans authorities have tightened security at airports and on city streets after deadly attacks on the Brussels airport and its subway system.

The Paris airport authority said security was tightened at all Paris airports soon after the Brussels explosions on Tuesday morning. Airports in London, Prague, Amsterdam and Bucharest, Romania, also saw increased security.

The attacks come just days after the main suspect in the Nov. 13 Paris attacks was arrested in Brussels on Friday.

The British and Polish governments convened emergency meetings as they beefed up security at airports.

Austrian Interior Ministry spokesman Karl-Heinz Grundboeck said more police are on the streets and at airports in Vienna and other major Austrian cities even though there appears to be no "Austria connection."