More than 400 people were killed and 265 wounded in an airstrike by Pakistan on a drug rehabilitation center in Kabul, a spokesperson of the Afghan Taliban government said on Tuesday, in the deadliest incident since fighting between the two began in October last year.

Pakistan rejected the statement as ⁠false and misleading and said it had “precisely targeted military installations and terrorist support infrastructure” on Monday night.

The airstrike on Kabul came hours after China said it was ready to continue mediating efforts to ease tensions and urged both states to return to negotiations.

Mediation efforts by Qatar, Turkey and Saudi Arabia had previously failed.

Amir Khan Muttaqi, the Taliban’s foreign minister, said Afghanistan had lost trust in Pakistan’s intentions regarding a diplomatic solution, according to a statement from his office.

The conflict is the worst between the South Asian Islamic neighbors, who share a 2,600-kilometer (1,600-mile) border.