Kenya's President William Ruto on Wednesday declined to sign a highly contentious finance bill that has sparked nationwide deadly protests, and has sent it back to parliament for amendments, Kenya's Star newspaper and KTN News reported.

Police opened fire on crowds who massed around parliament on Tuesday and later broke into parliament buildings, minutes after lawmakers had voted through tax hikes seeking to raise an additional $2.7 billion.

Kenyan protesters vowed on Wednesday to keep up their demonstrations against new tax hikes, a day after violent clashes outside parliament and across the country left at least 23 people dead and scores wounded.

The Star newspaper reported it had been informed by sources in Ruto's office the President has proposed a raft of amendments which members of parliament will have to consider.

Ruto, who is facing the most serious crisis since coming to power almost two years ago, will address the nation at 1300 GMT, his office said.

(Reporting by Hereward Holland Editing by Bate Felix)