The peace of Kenya's Deputy President William Ruto was disturbed on Saturday after gunmen invaded his home.

Ruto was not home during the attack that left one officer from the elite police General Service Unit (GSU) seriously injured, a security official, who was not authorised to speak to the press, said.

"There are armed people who staged the attack and have shot the GSU officer and stolen his gun," the official said.

Security forces are trying to establish if there are still attackers in the deputy president's "expansive" home near the town of Eldoret, some 312km northwest of the capital Nairobi, a senior police officer said.

"More security personnel have been deployed and a security operation is ongoing," the officer said.

Ruto's running mate, President Uhuru Kenyatta, faces a tight re-election contest on August 8 against longtime opposition leader Raila Odinga.