A van driven by a suicide bomber exploded after ramming through a gate at the Chinese embassy in Kyrgyzstan on Tuesday, injuring three people, authorities said.

"As a result of the explosion, only the suicide bomber terrorist died. Security guards were injured," Kyrgyzstan's deputy prime minister Jenish Razakov told journalists at the scene.

Razakov said the three wounded were all Kyrgyz employees of the embassy and that they have been hospitalised. Local medics said their injuries were not serious.

Impoverished majority-Muslim Kyrgyzstan -- which borders western China -- has a history of political instability and battling Islamist extremism.

Authorities say the country faces the threat of attacks from Islamic State group jihadists after some 500 Kyrgyz left to fight for the group in Iraq and Syria.

Chinese officials have previously been targeted in attacks linked to radicals from China's mainly Muslim Uighur minority, which lives just across the border in the restive western Xinjiang province.

Law enforcement sources told AFP that a Mitsubishi Delica van smashed through a gate at the embassy on Tuesday morning before exploding in the centre of the compound close to the ambassador's residence.

A police source confirmed to AFP that the vehicle was driven by a suicide bomber and described the incident as a "terrorist attack".

China's foreign ministry condemned the attack as an "extreme and violent act" but refused to classify it as terrorism.

"We asked the Kyrgyz side to get to the bottom of this incident and hold whoever is behind this accountable," spokeswoman Hua Chunying told journalists.

- Houses shook -

Kyrgyz officials have not yet pointed the finger of blame at any specific group, and President Almazbek Atambayev ordered a "thorough investigation".

The country's national security committee said that a criminal case for "terrorism" had been launched in response to the incident.

Kyrgyz police sources put the strength of the blast at an equivalent of up to 10 kilos (22 pounds) of TNT, and one said body parts thought to be those of the attacker were found several hundred metres (yards) from the blast site.

Local residents told AFP that the blast had blown in their windows and caused their houses to shake.

An AFP journalist close to the scene said that damage could be seen on the embassy buildings and that police had cordoned off the area as emergency services worked.

Employees from the Chinese and nearby American embassy on the edge of the city were evacuated, the Kyrgyz emergency service said.

Kyrgyz foreign minister Erlan Abdyldaev told Chinese counterpart Wang Yi in a phone call that authorities would take the necessary measures to ensure the safety of Chinese diplomats, Kyrgyzstan's foreign ministry said in a statement.

The American embassy warned US citizens in Kyrgyzstan to "shelter in place" until more information emerged.

An economically troubled ally of Russia, Kyrgyzstan has seen two governments overthrown and ethnic violence claim hundreds of lives since it gained independence in 1991.

The authorities regularly announce that they have foiled attacks planned by IS in the country.

Security forces last year said they had engaged in several fatal shootouts with suspected "terrorists" in the capital Bishkek.

One of the three suicide bombers who carried out a deadly attack blamed on IS at the international airport in the Turkish city Istanbul in June was reported to be from Kyrgyzstan.

- Violence across the border -

Chinese officials in Kyrgyzstan have previously been targeted, with one shot dead in 2000 in an attack blamed on radicals from the Uighur minority.

In 2014 Kyrgyz authorities said they killed 11 people, including Uighur rebels, trying to cross into the country.

Violence has plagued China's northwestern region of Xinjiang, in recent years, sometimes spreading beyond it.

Beijing blames the violence on separatist Islamist terrorists with overseas connections while rights groups point to what they say is discrimination against the Uighurs' culture and religion.

Kyrgyzstan and the other ex-Soviet Central Asian nations have come under fire for using a purported terror threat as a pretext to silence criticism of their secular regimes.

Kyrgyzstan is gearing up to mark 25 years since independence from the Soviet Union with celebrations in Bishkek on Wednesday.