Multiple attacks on Nigerian students have been reported this week in Greater Noida, 18 miles southeast of the capital New Delhi.
Nine Nigerians were attacked, including five who were wounded and two who were hospitalized with undisclosed injuries, said Abike Dabiri, Nigeria's special assistant on foreign affairs and diaspora.
A Kenyan woman who claimed that she was also attacked was found to have made up the incident, said Dharmendra Singh, a senior police superintendent in Noida. Police have since dropped the case.
Police said the violence began over the weekend, following the death of a teenager in an alleged drug overdose.
His family filed a police report against five local Nigerian men, who have since been detained on suspicion of drug peddling, abduction and murder, police said.
A postmortem, however, did not confirm the theory of a drug overdose and the men were later released.
Following their arrest, African students gathered to peacefully demonstrate for their release, said Ezeugo Nnamdi Lawrence, university coordinator with the Association of African Students in India (AASI).
On Monday, a counterprotest by Indians turned violent. Police officer Amir Dikshit said about 500 to 600 people attacked two students in a shopping mall in Noida.
A shocking video posted online
by AASI showed dozens of men hitting, kicking and hurling metal objects at a man lying apparently unconscious on the floor.
An hour earlier, in a separate incident, another group attacked another Nigerian man, 27-year-old Auwal Aliyu.
Aliyu said he had left home to get food when he saw a "gang of men" approaching him and fled inside a shop.
"I went inside looking for help (but) they chased me out," he said. He was badly beaten and hospitalized.
Dabiri told CNN the attacks were a case of "mob action."
"The Nigerians that were attacked were completely innocent, they just happened to be black ... I have spoken to the leaders of the Nigerian community in India and a lot of them are indoors, they are scared," she said.
"They were worried about a mob that was gathering overnight."
She demanded the "prompt prosecution" of those involved in the attack.