NAIROBI, May 31 (Xinhua) -- Kenya's Rael Kiyara said Friday her course record of 2:31:22 set four years ago is safe despite a planned assault by Ethiopian runners in Sunday's Lanzhou International Marathon in China.

Kiyara, who is out injured, will not be lining up on Sunday in the Chinese city but believes it will be hard to run faster owing to the tough course and hot conditions.

"It was a good marathon and I did well to set the record. But I have to warn the pretenders to the throne, it will take more energy from them to equal or break the course record," she said.

Kiyara last raced at the Dongying Yellow River Marathon in May last year where she finished fourth.

However, she had incurred injuries that has drained her batteries even as she struggles to return to fitness.