Five Chinese nationals have been killed and five more injured in Tajikistan in attacks launched from neighbouring Afghanistan over the past week, Tajik authorities and China’s embassy in the Central Asian country said on Monday.

China’s embassy in Dushanbe, the capital, advised Chinese companies and personnel to urgently evacuate the border area.

It said that Chinese citizens had been targeted in an armed attack close to the Afghan border on Sunday. On Friday, it said that another border attack — which Tajik authorities said had involved drones dropping grenades — had killed three Chinese citizens.

Tajikistan, a mountainous former Soviet republic of around 11 million people with a secular government, has tense relations with the Taliban authorities in Afghanistan. It has previously warned of drug smugglers and illicit gold miners working along the remote frontier.

China, which also has a remote, mountainous border with Tajikistan, is a major investor in the country.

There was no immediate response on Monday from the authorities in Afghanistan to the Tajik statement.

But Afghanistan’s foreign ministry last week blamed an unnamed group, which it said was out to create instability, and said it would cooperate with Tajik authorities.

Tajik President Emomali Rahmon’s press service said on Monday that Rahmon had met with the heads of his security agencies to discuss how to strengthen border security.

It said that Rahmon “strongly condemned the illegal and provocative actions of Afghan citizens and ordered that effective measures be taken to resolve the problem and prevent a recurrence of such incidents.”

Tajikistan endured a brutal civil war in the 1990s after independence from Moscow, during which Rahmon initially rose to power. The country is closely aligned with Russia, which maintains a military base there.

Millions of Tajiks, a Persian-speaking nation, live across the border in Afghanistan, with Tajikistan historically having backed Afghan Tajiks opposed to the Taliban.