David Ford and his party's MP Naomi Long were both named on the parcels which were delivered to Parliament Buildings on Wednesday.

The Mayor of Larne, Alliance Party councillor Gerardine Mulvenna, was another representative to be sent bullets in the attack, which is being linked to the ongoing flag dispute.

Mr Ford described it as a further twist on the continued "assault on democracy and assault on democrats", adding it was not clear who sent the bullets.

What is absolutely clear is that it's adding to the atmosphere, it's adding to the fear and tension.

Alliance leader David Ford

"It's clearly something where people are now taking action way beyond anything that might have been expected to arise from a democratic decision of a local council," said Mr Ford.

Earlier this month, Ms Long said she was the subject of a death threat, and the homes and offices of a number of Alliance representatives were attacked.

The attacks follow a vote taken at Belfast City Council to only fly the Union Flag on designated days.

Packages containing bullets were also addressed to Sinn Féin MLAs Gerry Kelly and Alex Maskey.

Mr Kelly said the attacks were "obviously connected to the current protests against the democratic decision taken at Belfast City Council".

Demonstrations against the vote, which have been held in towns and cities across Northern Ireland, are in their third week.

"These protests are being orchestrated by loyalist paramilitaries and attended by members of the two main unionist parties," said Mr Kelly.

"Obviously protestors have been wound up prior to the decision in Belfast and those that have kept up the tension need to reflect on what they have created."

This is obviously a step up in the attempt to intimidate elected representatives.

North Belfast Sinn Féin MLA Gerry Kelly

The politicians said the actions of those behind the death threats and bullets would not deter them from carrying their political duties.

An Assembly spokesperson said: "A package was delivered to Parliament Buildings today and intercepted by security staff."

Police confirmed they dealt with a number of suspicious packages found in the post room at Stormont.

Meanwhile members of Lisburn City Council are to re-examine how often the Union Flag is flown at the city hall.

On Tuesday night, DUP and UUP councillors voted for the policy of designated days to be reviewed.

But Alliance Party members and nationalists were left angered by the decision, and they said it is not the time to open a new front in the flag dispute.