Vastavam web: A Nigerian national was detained at the international airport here Sunday, as his visa was valid only till September 2. Upon his arrival from Frankfurt, Germany around 2 AM, the immigration authorities found that his visa was valid only till September 2. “We found that his visa was not valid beyond September 2. So we are deporting him back tonight,” an immigration official said. The Nigerian tried to escape from the airport, but was caught by security personnel, the official said.