BEIJING - Chinese Foreign Ministry spokesman Ma Zhaoxu said here Tuesday that several leaders of foreign countries are to attend the first China-Eurasia Expo in the northwestern Chinese city of Urumqi.

Pakistan President Asif Ali Zardari, Kyrgyz President Roza Otunbayeva, Azerbaijan's Vice Premier Abid Sharifov, and Kazakhstan's Deputy Prime Minister Aset Isekeshev are scheduled to attend the expo, at the invitation of the organizing committee of the expo, Ma said in a press release.

Li Jingyuan, secretary of the expo's executive committee, said at a press briefing that Chinese Vice Premier Li Keqiang is expected to attend the expo.

The expo will be held from August 31 to September 5.

Authorities have boosted security in Urumqi.

Fully-armed, rifle-toting police were seen guarding the convention venue located in suburban Urumqi, capital of Xinjiang Uygur Autonomous Region, on Tuesday, two days before the expo's official opening.

SWAT (special weapons and tactics) teams were deployed to handle security checks at the entrance.

Authorities declared a low-altitude "no-flight zone" in areas around Urumqi, effectively banning anything from light aircraft to hot-air balloons during the expo. Pigeon flying has also been banned.

Airports in a dozen cities, including Beijing and Shanghai, have been tightening security screenings for Urumqi-bound flights since Sunday. Passengers are asked to remove their shoes and have their carry-on luggage opened.

The increased security comes amid a two-month crackdown on terrorism ordered by regional authorities earlier this month following an outbreak of violence in Xinjiang's major southern cities, Kashgar and Hotan, that left at least 40 dead and dozens injured. A unit of the Snow Leopard Commandos, an elite counter-terrorism force under the People's Armed Police, has been deployed to the region from Beijing.

"Security is paramount," said Yu Xiudong, a senior member of the expo's organizing committee, on Tuesday. "We should make meticulous preparations against all security emergencies to ensure a safe expo."