The police cracked down on the Opposition Bangladesh Nationalist Party (BNP) on Monday, detaining senior leaders and raiding its office, as the party called a strike for Tuesday, after unidentified activists exploded six crude bombs at a rally.

The police detained BNP acting secretary general Fakhrul Islam Alamgir at the party office after “the BNP activists turned unruly, prompting our intervention to maintain public order.”

Other leaders were detained after a clash erupted when six bombs exploded at the rally to protest what the BNP alleged were mass killings, repressions, the filing of false cases after the continuing violence linked to the 1971 war crimes trial. Authorities called out paramilitary forces to guard Dhaka streets to prevent “subversive activities.”

Witnesses said the police stormed the BNP central office at Nayapaltan after clashes rocked the capital, with the Opposition activists workers the police, who retaliated with rubber bullets and tear-gas, turning parts of central Dhaka into a battleground for nearly an hour.