Islamabad, Jan. 28 (PTI): Pakistani police detained hundreds of Islamic activists threatening to disrupt a mixed-sex marathon in Lahore tomorrow on the grounds that it was "un-Islamic," as authorities beefed up security for the race.

Thousands of police personnel have been deployed to ensure that the international marathon race planned by the Punjab Provincial Government goes ahead peacefully. The alliance of Islamic groups, Mutahida Majlis Ammal, (MMA) is opposing the race, saying Islam prohibits women from participating in such races.

While the police said 100 Islamic activists have been arrested, the MMA claimed that around 2000 of its activists have been detained over the past two days.

MMA leader Liaqat Baloc told reporters the police conducted raids on the houses of Jamaat-e-Islami workers and leaders in Lahore and arrested more than ten people today. A Jamaat-e-Islami spokesman said 500 people were arrested in Lahore alone.

Arrests have also been made in other major cities including Faisalabad, Sialkot, Gujranwala, Ultan, Sahiwal, Okara, Kasur, Norwal and Toba Tek Singh, he said. Central Information Secretary of MMA Pir Ejaz Hashmi, and central leader of Jamiat ulema-e-Islam Riaz Durrani, are among those arrested. "The arrested activists have been arrested and expelled from Lahore," Baloch said.

"Arrests can't stop our struggle against marathon," Baloch said adding MMA workers will hold peaceful demonstration against the race. Organizers say that some 12,000 people, including 2000 women, from 16 countries have registered themselves for the marathon.