BEIRUT, April 23 (AP). — A state of emergency was declared throughout Lebanon tonight after anti-government riots in which at least 10 died and scores were wounded.

The state of emergency will last until Sunday, Radio Lebanon said.

Demonstrators had spilled into the streets in Beirut, the capital; in the southern port of Sidon; and in the Bakaa Valley village of Barr Elias. Chanting slogans in support of the Arab guerrilla movement, they clashed in the streets with security forces.

The government admitted that the 10 persons died in fighting in Beirut, in the southern town of Sidon and in the Bakaa Valley, but unconfirmed reports said the total may be higher. Scores were injured and arrested.

In Beirut, machine-gun fire rattled through the streets as six armored cars were called into action.