TUNIS, Tunisia — A female suicide bomber wounded nine people, mostly police officers, on a busy avenue in Tunisia's capital on Monday afternoon, authorities said.

The 30-year-old woman set off the blast in Tunis just before 2 p.m. on Habib Bourguiba avenue, according to Interior Ministry spokesman Sofiene Zaag, quoted by the TAP news agency.

The Interior Ministry said in a statement that the suicide bomber, who wasn't previously known to authorities, blew herself up near a police patrol. It said eight police officers and one civilian were wounded. Apart from the bomber, there have been no further reported deaths.

An AP reporter at the scene saw ambulances arriving to take the wounded to hospitals. The avenue, as well as several adjacent streets, was cordoned off by police.

Zaag was quoted by TAP as saying the explosion took place in front of Tunis' city theater. Habib Bourguiba avenue is considered the cultural, political and economic heart of Tunis — and is sometimes called Tunisia's Champs Elysees.

Tunisian radio station Mosaique FM said the attacker was wearing a homemade bomb belt with a small quantity of explosives. The station cited a security source it did not name.

It said the bomber came from the Mahdia region of eastern Tunisia and was previously unknown to security services, which raided her home after the attack.

Tunisian authorities have been on high alert in recent years following a spate of attacks including a deadly shooting in Tunis' Bardo National Museum in 2015 in which 22 people, including many European tourists, died. Three months later, an Islamic extremist attack in the beach resort of Sousse killed 38 people, mostly British tourists.

In November that year, a suicide bomber blew himself up on a bus carrying members of the Tunisian presidential guard, killing 12 on a main Tunis road. The Islamic State group later claimed responsibility.