Two men on Tuesday vandalised a portrait of President Jacob Zuma posing as Lenin with his genitals exposed in a Johannesburg gallery, as a court battle over the painting got under way. The face, stomach and genitalia of the painting was smeared with black paint which was also splattered on the while marble floor of the gallery. A red X was painted over Zuma\'s face and genitalia before black paint was smeared across the image, according to images shown on the local eNews television station which captured the two men defacing the painting. The vandalism occurred as about 400 supporters of the ruling African National Congress sang and danced in downtown Johannesburg in support of Zuma during a court hearing on the party\'s request to force the gallery to remove the painting. Although the gallery had stepped up security, deploying armed private guards, with a notice warning that visitors would be subject to security searches, witnesses said the two men managed to sneak into the gallery with small tins of paint. \"The white middle-aged man was the one who started it off and a young black man finished it off,\" Lance Claasen, a Khaya FM radio reporter who witnessed the defacing, told AFP. The gallery was closed shortly after the attack as a curious crowd gathered outside. Two police vans were parked outside the gallery in Johannesburg\'s upmarket Parkwood neighbourhood. Gallery spokeswoman Lara Kossef said \"there was a lot of shouting and screaming and a bit of physical jostling\" during the attack. The gallery is yet to decide on its next action. Sipho Sithole, a supporter of the ruling African National Congress (ANC) who was outside the gallery, supported the vandalism. \"It\'s sad I wasn\'t here (during the attack) because I would have bought more paint, we would have painted the whole building black,\" he told AFP. On the other side of the city, ANC supporters sang and danced demanding the painting be removed while the High Court heard an urgent application against its exhibition. The case was postponed to Thursday, when a full bench of judges will decide if the artist\'s right to freedom of expression trumps Zuma\'s privacy. Dressed in the party\'s green, black and gold, men and women sang anti-apartheid anthems in Zulu and brandished placards in front of an ANC truck and large television screen. A few youths briefly held up a poster showing a naked picture of the opposition Democratic Alliance (DA) leader Helen Zille, who is white. The roads around the court were closed and riot police guarded the entrance to the domed building. No violence was reported. Julia Muludzi, 65, carrying a poster reading \"Hands Off Our President. We Are Hurt,\" said the painting was disrespectful. \"They are trying to sabotage our government because they want to go back to apartheid. It\'s racism,\" she told AFP while swaying to the songs in her ANC wrap-around. Another said the depiction violated African culture. \"Our culture is very much against that. You can never refer to someone\'s private parts,\" said Elizabeth Mabaso, 58. \"If our president was a white person they wouldn\'t do that.\" The polygamous president generated national debate when he married for a sixth time last month and has four current wives. He has 21 children, including several out of wedlock. A few veterans of the ANC\'s military wing also protested outside the court. \"He can marry as many women has he wishes,\" said Sidwell Modisane, a 42-year-old vet dressed in military fatigues.