An ISIS member slipped by Taliban security barriers “before blowing up his explosive belt in the middle of employees and guards”, the Amaq news agency of the local chapter of the extremist group said on the Telegram messaging app.
The local ISIS branch, known as Islamic State-Khorasan, claimed that the blast killed at least 20, including “several diplomatic employees”.
Kabul police spokesman Khalid Zadran said five civilians were killed and several more wounded by the blast.
The bombing was the latest claimed by ISIS in a string of attacks on foreigners or foreign interests in recent months.
The attacks come at a time when the Taliban are trying to attract foreign investment to prop up an economy that has suffered under Afghanistan's international isolation after they seized power in August 2021.
At least five Chinese citizens were wounded when gunmen stormed a Kabul hotel popular with Chinese business people on December 12.
The attack came days after militants stormed Pakistan's embassy in Kabul in what Islamabad said was an “assassination attempt” against its top diplomat there.
Both attacks were claimed by ISIS, as was a suicide bombing at the Russian embassy in September.
According to the Taliban's Deputy Minister of Information and Culture, Muhajer Farahi, a Chinese delegation had been scheduled to visit the Foreign Ministry on Wednesday.
However, Ahmadullah Muttaqi, a senior official in the Prime Minister's office, said no foreigners were present at the ministry when the suicide bomber struck.
"As far as we know, there were no Chinese citizens killed or injured in this terrorist attack," Chinese Foreign Ministry spokesman Wang Wenbin said on Thursday.
China hoped "the Afghan side will take resolute and effective measures, earnestly protect citizens and institutions from all countries, including the Chinese side, that are in Afghanistan", Mr Wang said when asked about the attack during a press briefing.
Neighbouring China is one of the few nations to maintain diplomatic ties with Afghanistan's new rulers.
Beijing has not recognised the Taliban government but has been interested in Afghanistan's vast mineral deposits, which were largely impossible to exploit during the 20-year war that followed the end of the Taliban's previous reign in late 2001.
— With reporting from agencies