At least 20 people were killed and dozens injured in Karachi on Monday when a suicide bomber attacked a Shiite Muslim procession, Pakistan's Aaj TV reported.

The blast went off on Jinna Road in the city center while worshipers were celebrating the holy day of Ashura.

No groups have yet claimed responsibility.

The attack is the second in two days committed against Shiites in Pakistan. On Sunday, a suicide bomber blew himself up near a prayer hall in city of Muzaffarabad in Pakistan-administered Kashmir. Eleven people were killed and some 50 injured.

The blast took place despite tough security measures taken by Pakistani authorities during celebrations of Ashura, which commemorates the killing of Imam Hussein, a grandson of the Prophet Mohammed.

Several radical Sunni groups, including Lashkar-e-Jhangvi, which aims to turn Pakistan into an entirely Sunni state, are active in the country. The groups regularly carry out attacks against Shiites.

Hundreds of people have died in Pakistan due to Sunni and retaliatory Shiite attacks in recent years.

MOSCOW, December 28 (RIA Novosti)