Taiwan said Kenyan police broke down a jail wall and used teargas to force a second group of Taiwanese to board a plane for China, a day after accusing Beijing of abducting eight other citizens.

The 15 Taiwanese were being held in a police station despite being cleared by a Kenyan court of involvement in a cyber-scam, the foreign ministry said.

Taiwan’s representative in Africa was informed early on Tuesday that Kenyan police were trying to remove the 15 people from the station and send them to China, it added.

“Our colleague went immediately to the prison to see the detainees but faced all kinds of impediments,” said Chen Chun-shen, chief of west Asian and African affairs at the ministry.

“They refused to cooperate with the deportation … so the police broke down the walls, using teargas, and then more than 10 police went in with assault rifles,” Chen told reporters in Taipei.

Three people from China’s Kenyan embassy were present, he said. Taiwan has no diplomatic ties with Kenya and its nearest diplomat is based in South Africa.

There was no immediate confirmation the 15 had left for China.

Taipei has already strongly protested to Beijing over the earlier deportation of eight Taiwanese who were also cleared in Kenya of cyber-fraud charges.

It accused China of kidnapping the eight and demanded their immediate return. One of the eight has an American passport, Taiwan’s foreign ministry said.

Another 22 Taiwanese arrested just last week over similar allegations were also expected to be sent to China on Tuesday, it said.

The authorities in China have not confirmed details of the deportations and Taipei is still seeking a response.

When asked about the incidents, China’s foreign ministry spokesman Lu Kang said: “The One China policy is an important precondition for bilateral relations with China and other countries.

“We commend Kenya for its upholding of this policy,” he told a regular briefing.

China still regards Taiwan as part of its territory – awaiting reunification, by force if necessary – even though Taiwan has ruled itself since 1949.

Taiwan’s previously frosty relations with the mainland have improved over the past eight years under outgoing president, Ma Ying-jeou, whose Kuomintang party has a tacit agreement with Beijing to acknowledge there is “One China”.

But the latest episode has angered both the government and the opposition.

The mainland is stepping up pressure on Taiwan president-elect Tsai Ing-wen – who is due to take office in May – as Beijing does not trust her historically pro-independence party.

Tsai condemned what she called the abduction by the mainland in a Facebook post on Tuesday and called for the release of the citizens.

“This incident will deepen the negative perception of the mainland in Taiwan’s society,” she said.

The mother of one of the men forcibly removed from jail on Tuesday told Apple Daily newspaper he was in Kenya on holiday with friends.

He was part of a group of 28 Taiwanese and 49 other ethnic Chinese arrested in November 2014 on charges of illegally entering the African state and being involved in fraud.