Speaking in Parliament on Tuesday, he said, "European citizens must be informed: in the Democratic Republic of the Congo (DRC) we run the risk of facing a new genocide. Especially in the eastern Kivu region, brutal militias massacre unarmed people every day in order to expel the population and take full control of the exploitation of natural and mineral resources.
"All this meets with indifference from the international community and inaction from the African Union."
His comments come after the New York-based Human Rights Watch recently said that peacekeeping troops from Congo Brazzaville have killed civilians, including women and children, in the Central African Republic.
Human Rights Watch said the Congo Brazzaville government "has still not taken any action towards a credible investigation or justice for these crimes."
Pittella addressed the issue when he spoke at a news conference in Strasbourg at the start of Parliament's monthly plenary session. His intervention comes with tensions rising in the eastern region of the DRC ahead of planned elections later this year.
The Italian MEP, who visited Congo with a Parliament delegation last year, said, "Europe cannot remain silent faced with a possible repeat of the tragedy in Rwanda.
"We need a comprehensive strategy that envisages not only military action but also political action. It is evident that the UN stabilisation mission in the DR Congo (Monusco) has been unable to protect civilians - as the recent massacre in the city of Beni demonstrated.
"On behalf of the group, we call on the EU's foreign affairs chief, Federica Mogherini, to launch an international inquiry into these massacres, in collaboration with the United Nations and the International Criminal Court. We also urge the European members of the Security Council to take all possible action within the Council in order to stop these crimes."
Pittella added, "The group has proposed a resolution on these massacres in the next plenary of the European Parliament. We expect other groups to support this initiative. These crimes against humanity cannot go unpunished."
He said that since his visit to Congo the situation in the country had "worsened."
Demonstrators clashed with police in the eastern Democratic Republic of the Congo last month after opposition leaders called for a day of countrywide protest against President Joseph Kabila over indications that November elections will be postponed.
The United Nations, EU, Africa and the French-speaking world issued a rare joint statement on Monday highlighting growing concern at rising political tensions in Congo ahead of the elections where some fear Kabila may try to stay in power despite being constitutionally barred from a new term.
The UN, EU, African Union and International Organisation of La Francophonie underlined "the crucial importance of holding a successful political dialogue" with all Congolese parties that leads to a consensus on holding free, transparent and credible elections.
The DRC is nearly two-thirds the size of western Europe and has a population of more than 79 million. Since it won independence from Belgium in 1960, there has never been a peaceful, democratic transition of power in the country.