TAIPEI (AFP) — Taiwan detected six Chinese balloons off the island, the defense ministry said Friday, as Beijing maintains military pressure to push its claim of sovereignty.

The six balloons were spotted in the 24 hours to 6:00 a.m. on Friday, the ministry said, giving one of its highest daily tallies of the devices.

Along with the balloons, nine Chinese military aircraft, six warships and two official ships were detected near Taiwan over the same period.

The balloons were spotted at an altitude of 16,000 feet to 20,000 feet, and one of them directly flew over the island, according to an illustration released by the defense ministry.

While Taiwan calls itself a sovereign nation, China claims the island and has threatened to use force to bring it under its control.

In recent years, China has ramped up the deployment of fighter jets and warships around the self-ruled island and sought to erase Taiwan from the international stage by poaching its diplomatic allies and blocking it from global forums.

Chinese balloons have been regularly spotted over waters near Taiwan in the past few months, but Friday’s figure is one of the highest recorded, according to an Agence France-Presse tally of the military data.

Last year, Taiwan detected a record of eight Chinese balloons less than a month after the presidential elections won by the ruling Democratic Progressive Party’s Lai Ching-te.