AT LEAST 20 people, including seven police officers, were injured in clashes between police and anti-austerity protesters at mass demonstrations in Madrid yesterday. Three people were arrested.

Riot police sought to prevent the protesters from entering the city’s main square for the third day in a row, the AFP reports.

The Puerta del Sol square has been the focal point of demonstrations against the government’s austerity measures aimed at tackling Spain’s debt. The interior ministry ordered the square’s closure earlier this week after 79 days of its occupation by demonstrations, and protesters were forced to leave it on Tuesday.

El Pais reports that several hundred protesters who wanted to regain access to the square headed to the interior ministry last night, but the group was blocked and charged by riot police.

Amateur footage posted online by Euronews shows the crowds gathered last night and some who were injured in the later violence:

Yesterday, the ECB decided to maintain its key interest rate amid growing concern over the stability of the Spanish and Italian economies, as the European Commission’s President Jose Manuel Barroso warned that the region’s debt crisis is spreading.

Stock markets have performed badly in Asia and Europe since opening this morning amid fears over Eurozone debt and the strength of the US economic recovery.

Read: European markets open… and it’s not good news >