Pakistani authorities say at least 30 people were killed and more than 50 others injured in a suspected suicide bombing near a Shi'ite mosque in central Pakistan Thursday.

Police say the blast in the city of Dera Ghazi Khan occurred as a religious procession was passing the mosque.  

There was no immediate claim of responsibility, and the motivation for the attack is not clear.

Most Pakistanis are Sunni Muslim, while Shi'ites make up about 20 percent of the country's population.

Also Thursday, Poland's Foreign Ministry said Pakistani Taliban militants who kidnapped a Polish geologist last year have extended a deadline for the Pakistani government to meet their demands. The ministry did not provide further details.

Piotr Stanczak, who works for Geofizyka Krakow, was abducted in Punjab province on September 28. Three Pakistanis were killed during the kidnapping.

Some information for this report was provided by AFP, AP and Reuters.