Former Pakistan Prime Minister Imran Khan on Thursday gave a six-day deadline to the Shehbaz Sharif-led government to announce fresh elections in the country, Dawn reported.

Khan gave the ultimatum after his supporters entered capital Islamabad as part of a protest rally against the government.

“No blockade can stop us,” Khan said while addressing his supporters in Islamabad, according to Reuters. “We will remain in Islamabad till the announcement of dates for dissolution of assemblies and elections is given.”

Supporters of Khan’s Pakistan Tehreek-e-Insaf party have been holding protests across the country against the government ever since the former cricketer-turned-politician was ousted from power after losing a no-confidence vote on April 10. He has repeatedly claimed that the vote was part of a “foreign conspiracy” to topple him.

Clashes have been reported between Khan’s supporters and security forces in several cities, including Karachi and Lahore, according to Reuters.

During Thursday’s speech, Khan claimed that five of his supporters have been killed in clashes with the security forces across the country.

The 69-year-old said while he had received information that three were killed in Karachi, one of his supporters had fallen off the Attock bridge amid tear-gas shelling in the Khyber Pakhtunkhwa area and another was pushed into the Ravi river by the security forces, according to PTI.

The government has not confirmed the deaths.

The Pakistan government, however, has opposed the protest march by Khan saying it threatens stability in the country.

“It has been my conviction that Pakistan will progress only through sheer hard work,” Pakistan Prime Minister Shehbaz Sharif wrote on Twitter on Wednesday. “Politics of dharna [protest] is detrimental to progress and stability. We are focused on overcoming the challenges of governance. Nothing can distract us from the task at hand. I owe it to the people of Pakistan.”

Meanwhile, as the unrest due to Khan’s protest rally grew in Islamabad on Thursday morning, the government called in the army to protect government buildings in the city’s red zone.

“The federal government is pleased to authorise the deployment of sufficient strength of troops of Pakistan Army in Red Zone under Article 245,” the country’s Interior Minister Rana Sanaullah said tweeting the announcement.