Cape Town - Revenge attacks and an intricate gang battle over turf apparently led up to the shooting of suspected gangster boss Jerome "Donkie" Booysen at the Cape Town International Airport on Wednesday, as well as the double murder at a Stellenbosch nightclub last week.The incidents have highlighted how gang violence has no boundaries.Sources with close knowledge of the matter say clashes between the numbers gangs - the 26s, 27s and 28s - sparked the shootings.The attack on Booysen at the Cape Town International Airport on Wednesday is said to be in retaliation for the shooting at Cubana in Plein Street, Stellenbosch, last Saturday. A second man was also struck by a stray bullet in the airport shooting.Donovan Jacobs, who sources identified as a 28s gang member, was killed in the Stellenbosch incident, as was Nicole Muller, 30, a mother of two young boys from Kuils River, who was at the club to celebrate a friend's 30th birthday.Sources have told News24 that Jacobs had been the target of that shooting and that Booysen was shot on Wednesday morning in retaliation for this incident. Police have not officially said this.Further retaliation, sources say, is expected.For a detailed breakdown of underworld activities in the Western Cape see News24's Underworld Unmasked showcase here.Four years ago, Booysen - who used to be involved in a company which dominated nightclub security around Cape Town - was named in a court case as the head of the Sexy Boys gang. Nothing ever came of this.The numbers gangs are linked to underworld figures who are said to be involved in the nightclub security scene.Over the course of about seven months, four other innocent people have been wounded in other underworld shootings involving Cape Town venues.These incidents have shown that underworld gang wars have spilled over from the streets of suburbs historically plagued by gangsterism, into establishments and areas not necessarily known for violence.WATCH: How Cape Town’s violent underworld takeover is escalatingThe shooting of Booysen inside the Cape Town International Airport, as well as the shooting inside Cubana in Stellenbosch last week, also shows how gang violence has converged with unrelated activities in seemingly safe spaces.'Revenge attacks'News24 understands that Booysen, who was targeted in two other previous shootings this year, was chased into the airport on Wednesday morning, shortly after he had arrived there. It is understood he was wounded four times - in the stomach, leg and arm.Sources said it was believed the 28s gang was behind the shooting.In the Cubana incident in Stellenbosch, on Saturday shortly after midnight, Jacobs, 40, a reported convict from Delft, ran into the establishment because two gunmen were pursuing him. The two gunmen, according to witnesses, opened fire inside the venue.Muller was caught up in this shooting. A third person was also wounded.'My daughter is just another statistic'Muller, according to a post on her father Tony Absolon's Facebook page, was killed as she was preparing to leave the venue.In the post, he said: "Celebrating her friend's birthday and about to come home she was caught in the crossfire as she and her friends exited the Cubana club…"Yes my FB friends, my daughter has become just another statistic in this messed up country of ours. Where is the justice, so many unanswered questions. Yes I am extremely angry but deep in my heart I know It was God's will and she is in a better place rigt [sic] now."Absolon described his daughter as the "livewire" of his family.A memorial was set to be held for her in Kuils River on Wednesday.Increased gang shootingsThere has been a surge in shootings, particularly gang-related ones, in the Western Cape recently.The situation reached such an extent that last week Police Minister Fikile Mbalula called for the army to be deployed in the province to help police clamp down on violence.READ: Mbalula asks army to help quell violence in WC and GautengHe said Cape Town was a violent crime hot spot.This year it has also been the scene of a nightclub security takeover which has sparked violence and several shootings.Nightclub security takeoverControversial businessman Nafiz Modack is heading a group intent on taking over nightclub security in both Cape Town and Johannesburg.Modack is taking over security operations from a more established grouping.READ ALSO: EXCLUSIVE: People want me dead because of my security industry connections – underworld figure ModackWhile Modack has denied being affiliated to any gang, some underworld figures have ties to different gangs.Some sources say rival 27s gangsters have been targeting the 28s, as well as the 26s.News24 understands the 26s gang works with the Sexy Boys gang.But according to sources with close knowledge of the situation, there have recently been shifts in the 26s and Sexy Boys gangs.Gang 'shifts'A prominent member of the 26s and Sexy Boys gang is said to have been ousted and then apparently went on to become a 27s gang member.Therefore, the 27s were also, in a manner, linked to the Sexy Boys gang.The 26s and 27s are apparently fighting to dominate club security.On top of the this, the sources said, the 28s gang was trying to muscle in as they wanted to control some club security and allegedly the drug trade.Previous shootingsIn a previous shooting, alleged 28s boss Ralph Stanfield was wounded in Melrose, Johannesburg, on July 6.Booysen was previously shot at in September in Bellville South. He was not wounded.On May 8 he was wounded in a shooting in Elsies River. Sources said Booysen had been on his way to visit another man, who was also shot, in the Cravenby area.Patrons of Cape Town establishments have also been wounded in shootings.READ ALSO: Another person shot at Cape Town nightclub as 'underworld turf war' continuesOn April 17, two men were wounded in Café Caprice in Camps Bay.In an exclusive interview with News24 in September, Modack said he had been the target of the Café Caprice shooting.On May 5, a patron and a DJ were wounded in a shooting, which happened just outside Coco nightclub in the Cape Town city centre.Several arrests have been made for these shootings.A task team headed by the Hawks has been set up to investigate underworld and nightclub violence.