MANILA (REUTERS) - The mayor of the major financial hub in the Philippines said on Wednesday (March 21) she was investigating after a pornographic video appeared briefly on a prominent billboard, startling motorists on one of the bustling city's major roadways.

The video appeared for about half a minute on an electronic billboard at a busy intersection on the main road through Makati City, the central business district of the sprawling capital, Manila, on Tuesday afternoon.

Makati Mayor Abigail Binay immediately ordered the billboard shut down after the clip of a couple having sex was shown, but pictures and videos of it captured by motorists on their mobile phones were shared widely on social media.

The billboard will remain closed pending the results of an investigation, Binay said. That investigation will include whether the billboard's owner, Philippine company Globaltronics, or its employees were responsible, a statement from her office said.

Pornography is illegal in the predominantly Catholic Philippines, which also strictly regulates television and movie content. Adult website Pornhub said last year the Philippines ranked 13th in the world for daily visitors.