A 14-year-old boy has been charged with murder over the fatal stabbing of schoolboy Daniel Awak, as Adelaide police braced for possible retaliation within the city’s Sudanese Australian community.

Police would not confirm whether the accused also was allegedly involved in the stabbing of a second Sudanese Australian boy during the brawl in central Adelaide’s Grenfell Street on Wednesday.

The injured boy on Friday remained in a critical condition.

Police said earlier they had not yet identified a clear motive for the deadly attack but understood a number of altercations had led to the brawl, which involved about 12 Sudanese Australian youths, all from the same tribal group, fighting with knives in the city’s centre.

Senior police met on Friday with leaders of Adelaide’s 1,500-strong Sudanese community.

South Australian Police Commissioner Mal Hyde said relations between police and Adelaide’s Sudanese community were good, but officers were concerned about the possibility of retaliation in the community.

As a safety measure, police would undertake extra patrols in key areas of the city where Sudanese youths were known to gather or frequent, he said.

With knife attacks on the rise, the commissioner also said he wanted to see metal detectors more widely used to help police crack down on knife carriers.

“We need to look at the circumstances in which police can search for these dangerous weapons,” he said, acknowledging police could not prevent every knife attack.

“But we need to make sure that a culture doesn’t grow where the carrying of knives, particularly among some groups, becomes the norm.

The family of Daniel, a 14-year-old schoolboy, held a news conference on Friday and said they did not harbour hard feelings over his death.

“He died probably because he was in the wrong place at the wrong time,” Daniel’s uncle, Bol Machar, told ABC radio.

“Thongjang (Daniel) was a bright boy, caring, loving, and mingled with other people very well. “We love him so dearly, we are proud of him and we miss him a lot,” he said.

The boy charged with his murder will appear in the Adelaide Youth Court on Monday, police said.

A 16-year-old boy was arrested at the scene of the attack and charged with aggravated assault on police and resisting arrest.

Hyde also said laws should be amended to stop the scourge of knife crimes from spreading.

Current laws allowed people to come up with “flimsy, invented and spurious” reasons for carrying knives, he said.

“When we look around the world, you’ll see that some countries do have serious problems with the carriage of knives and assaults with knives, including murders.”