ISLAMABAD (AP) — Shaken by multiple militant attacks, Pakistani authorities have locked down the capital in a major security move as senior officials from several nations arrive for an Asian security group meeting.

A three-day holiday started Monday in normally bustling Islamabad and the nearby garrison city of Rawalpindi, and Pakistan has deployed troops and blocked key roads, making it difficult even for ambulances to pass through. Some doctors asked police to remove barricades so that they could go to hospitals, but were instead asked to take longer routes.

The main event of the Shanghai Cooperation Organization will be held Wednesday, when leaders and officials discuss how to boost their security cooperation and economic ties. The group was founded in 2001 by China and Russia to counter Western alliances. Other members include Iran, India, Pakistan, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan.

Militants in recent weeks have killed dozens of people in multiple attacks in restive northwestern and southwestern Pakistan bordering Afghanistan. Security experts say militants have limited capacity to strike in Islamabad.

Pakistan often blames the outlawed Pakistani Taliban, who have sanctuaries in neighboring Afghanistan, for the violence. Afghanistan’s Taliban government says it does not allow anyone to use its soil for attacks against any country.

Two Chinese engineers were killed on Oct. 6 in a suicide bombing outside the airport in Karachi, the capital of southern Sindh province. The attack was claimed by a separatist group.

In the past, ordinary Pakistanis used to line up on both sides of the main roads to welcome any dignitaries visiting the country, but authorities said they had to take harsh security measures because of fears of militant attacks. Only state media will be allowed to cover the meetings.

Among those attending were China’s Premier Li Qiang, Russian Prime Minister Mikhail Mishustin, India’s External Affairs Minister Subrahmanyam Jaishankar, Iran’s First Vice President Mohammad Reza Aref and the prime ministers of Kyrgyzstan, Belarus, Kazakhstan, Tajikistan and Mongolia.