Islamabad, Sep 4 (IANS): Polling is underway in Pakistan Parliament here and the provincial assemblies in Lahore, Karachi, Peshawar and Quetta to elect the country's 13th president via the secret ballot system.

In the running for the post are Dr Arif Alvi of the ruling Pakistan Tehreek-i-Insaf (PTI); PML-N backed chief of the Muttahida Majlis-e-Amal (MMA) Fazlur Rehman; and senior PPP leader Aitzaz Ahsan, Dawn reported.

A joint sitting of the Senate and the newly elected national and provincial assemblies -- together known as the electoral college of Pakistan -- has been called to elect the new president.

The voting, which is being held simultaneously at the Parliament House and the four provincial assemblies, started around 10 a.m. and will end at 4 p.m.

The NA and Senate members are voting inside the National Assembly hall, whereas the MPAs are doing the same in their respective provincial assemblies.

The Election Commission of Pakistan has barred the members from carrying mobile phones with them at the time of voting.