Islamabad, Aug 15 (IANS): Opposition leader Imran Khan Friday said he was attacked by Pakistan Muslim League-Nawaz (PML-N) activists during an anti-government march in Pakistan's Punjab province, TV reports said.

The attack took place in the industrial city of Gujranwala, Dunya TV reported, adding that the PML-N activists hurled stones that smashed the window panes of Khan's vehicle.

At least four activists of Khan's Pakistan Tehreek-e-Insaf (PTI) were also injured in the attack.

Khan said it was the fourth time that they were attacked by PML-N activists, adding that the Sharif brothers (Prime Minister Nawaz Sharif and Punjab Chief Minister Shahbaz Sharif) will be responsible if any untoward incident happened during the anti-government march to the capital Islamabad.

The PTI leader said police took no action against the attackers and that he had the video evidence to support his claims. The miscreants were using the roofs of police vans to attack the marchers, a PTI activist was quoted as saying by Duniya TV.

Khan started his anti-government march from Lahore Thursday.

A former cricketing icon, he told hundreds of supporters at the beginning of the march that he was struggling for a "new Pakistan" as the rulers have "failed to deliver".

The marchers will reach capital Islamabad after covering a distance of nearly 370 km, where they will start a sit-in.

Khan said he would not end his protest until the prime minister resigned.

He claims that Sharif has formed the government through "rigging" in last year's General Elections, a claim rejected by the government.

Sharif has rejected calls for his resignation and accused Khan of trying to weaken his elected government.

Tahir ul Qadri, a senior religious leader who heads Pakistan Awami Tehrik or Peoples Movement, is also marching towards Islamabad along with his supporters and will join Khan in Islamabad.