Rome, April 28 (IANS/RIA Novosti) Italy and France are calling on other European Union (EU) countries to discus the imposition of sanctions against Syrian authorities to prevent further escalation of violence against protesters, Italian Foreign Minister Franco Frattini said Wednesday.

Addressing Italian lawmakers, Frattini expressed hope that the European Union would be able to discuss the issue as early as in May.

Frattini and his French counterpart Alain Juppe met in Rome Tuesday and demanded that an independent UN investigation be launched into the recent crackdown on protesters in the Middle Eastern country.

France, Britain, Germany, Italy and Spain summoned Wednesday respective Syrian ambassadors to condemn the use of violence against protesters by President Bashar al-Assad's regime.

Syrian mass protests started in Daraa on the border with Jordan March 18. They were prompted by the arrest of a group of schoolchildren who wrote anti-government graffiti on walls. The unrest later spread to other Syrian regions.

In response to the protests, Assad formed a new government, promised a score of political and economic reforms, and even lifted Tuesday the almost five-decade long state of emergency in the country.

However, these measures failed to pacify the opposition prompting the government to resort to violence in dealing with the protesters.

At least 450 protesters have been killed in five weeks of clashes with government troops and police across the country, according to the Syrian opposition.