South African police said today that security surrounding the Nigeria midfielder Sani Kaita would be stepped up ahead of their match against South Korea, after team officials claimed he had received over 1,000 death threats.

Kaita is banned for tomorrow's match after being sent off in Nigeria's second Group B match against Greece. His team were a goal up when he was sent off in the 33rd minute for kicking out at Greece's Vasilis Torosidis and went on to lose 2-1.

"Kaita has so far received more than 1,000 threats to his email from within Nigeria," said the team spokesman, Peterside Idah, yesterday. "We are taking these threats very seriously. We've spoken to the Nigerian government to inform them about it and also written to Fifa to notify them."

South Africa's national joint operational and intelligence structure said today that it had taken note of the reported death threats, which arrived via email and emanate from Nigeria.

The team's security liaison officer from the South African police service said the experienced officer assigned to Nigeria had been told to pay special attention to Kaita.

"The TSLO and close protectors travel everywhere with the teams and security around each team is very tight and of a high quality," said the police in a statement. "The TSLO with the Nigerian team has been requested to pay close attention to Mr Kaita and to ensure that the stringent security measures already in place are sustained."

The emailed death threats have also been reported to Fifa.

"We consider it a very serious matter because this is a young man who is putting his best at the service of his country and football," added Idah. "That is why the team received the news of the threat to his life with shock and disappointment and is urging the authorities in Nigeria to take measures to protect him."

He said the 24-year-old was "terribly shaken, but, fortunately, he is receiving great support from his team-mates and team officials".