The total number of protesters reached around 5,000 later on Thursday with the arrival of protesters carrying the flags of hardline Islamist groups. At least 50 people were injured as police fired tear gas and live rounds towards the crowds.
Hundreds of students from various colleges and educational institutions in Islamabad had begun clashing with police as security forces tried to block them from reaching the embassy compoud, which also includes the British and French diplomatic missions.
The students responded by pelting the police with stones, and the police retaliated by firing tear gas shells.
Al Jazeera's Kamal Hyder, reporting from Islamabad, said the situation was eventually brought under "control" by police and the military.
Click here to read more from Al Jazeera.