Up to 100 people have been arrested in Brussels this morning, in protest against the Transatlantic Trade and Investment Partnership, IBTimes UK has learnt.

Three of the arrested were members of the Belgian parliament, representing the ECOLO party. They are Anne Herscovici, Alain Maron and Ahmed Muhsin.

It's understood that the protest was up to 400-strong and that the arrests were made on the direct orders from the Mayor of Brussels, Yvan Mayeur.

The law in Belgium states that it is illegal to hold public protests without authorisation from the municipality. However, a spokesperson from ECOLO says the fact that three MPs were arrested made it "very unusual".

Police are alleged to have used water cannons to disperse the crowds, which had gathered outside the European Business Summit taking place in the city. The protest was organised by Allianz D19-20, a coalition of protest groups.

Talks over TTIP are due to resume on Monday, in the week running up to European Commission elections.

The summit hosts speakers from influential political circles, including the European Commission, as well as business leaders from the likes of McKinsey, L'Oreal, Citigroup and Exxon Mobil. TTIP is expected to be high on the agenda.

ECOLO spokesperson Franco Meggetto says that the party is "philosophically" opposed to TTIP, which he says will threaten European consumers. He pointed to the US use of ammonia in poultry breeding and its use of genetically modified organisms, which could be introduced to the European market if the treaty is ratified.

This week, IBTimes UK called on the treaty's architects and supporters to come clean over projected figures. An academic report has called into question the statistics widely cited around TTIP's likely benefit, suggesting they are largely inflated.

Protestors have taken to Twitter to post pictures and views from the protests, with some speculating that more than 200 arrests have now been made.