Pakistani authorities have arrested around 100 people on charges of betting on World Cup football matches, a crime in this conservative Islamic republic.

In their first crackdown since the tournament kicked off in Germany last month, law enforcement agencies raided an underground bookmakers in the southern city of Karachi.

"We got information that some people were involved in betting on football World Cup matches so we raided the building in a main shopping area and arrested some 100 people," Citizens-Police Liaison Committee chief Sharfuddin Memon told AFP Monday.

Gambling records and television sets were also seized and the case was handed to police for further investigation, Memon said.

Although Pakistan is not playing in the World Cup officials say there is a huge audience for the matches.

Betting is illegal in Pakistan but police have regularly arrested illegal bookies involved in betting on cricket and horse racing.

Pakistan had to conduct two match-fixing inquiries after some cricket players were allegedly involved in throwing games for money. Former captain Salim Malik was banned for life in 2000 after an inquiry.