New Delhi: The Congress on Tuesday questioned the silence of Prime Minister Narendra Modi on the attacks on Africans and said the attacks seem to have racist overtones. "The national capital has witnessed a number of incidents in recent months -- the targeted attacks on students from Africa and nationals who are citizens of African countries. It is unacceptable. It is shameful," said senior Congress leader Anand Sharma at a press conference here. "The President of the Republic has spoken, the Vice President has spoken. Prime Minister is silent. His silence is embarrassing now. He is the elected Leader -- head of the executive, head of the government. He must speak and his government must ensure the safety of students from Africa," added Sharma. Sharma also went on to say that the attacks do have racist overtones. "His minister should be careful. If the External Affairs Minister was trying to make a statement to control the damage, the Minister of State who has no experience of diplomacy, no sensitivity, gave an impression as if nothing had happened. These attacks appear to have racist overtones. We are making that clear, you cannot be in denial," said Sharma. "There has to be course correction and that must be done immediately. The Congress party expects that the Prime Minister, who talks on everything, will at least give a pause to his self-propaganda and comment on this issue," he added. External Affairs Minister Sushma Swaraj on Tuesday said that all criminal acts on Africans should not be construed as racial attacks.