Authorities in a broad swath of eastern Pakistan closed all parks and museums Friday because of record-breaking smog that already has prompted the closure of schools and government offices and has sickened tens of thousands of people.

The new restrictions went into effect for ten days in 18 districts of Punjab province, including the provincial capital of Lahore, where a twilight gloom lingered over the city, limiting visibility to about 100 meters (yards).

The closures apply to all public parks, zoos and museums, historical places, and playgrounds. Schools and government offices already had been closed until Nov. 17.

Toxic smog has shrouded Lahore, a city of 14 million people, and other parts of Punjab since last month, and health officials say more than 30,000 people have been treated for respiratory ailments in smog-hit districts.