Sessizlik saatleri ateş yakma yasağıyla birlikte açıklandı.

Sessizlik means silence or quietness.

It is built from:

• sessiz = quiet, silent
• -lik / -lık / -luk / -lük = a common suffix that makes abstract nouns

So:

• sessiz → quiet
• sessizlik → silence, quietness

In this sentence, sessizlik is used to describe the kind of hours being talked about: quiet hours.

Because Turkish often uses a noun compound here rather than a simple adjective + noun pattern.

• sessiz saatler would mean something like quiet hours too, but it sounds more like hours that are quiet
• sessizlik saatleri means more specifically hours of silence or designated quiet hours

This is a very common Turkish pattern:

• öğle yemeği = lunch
• otobüs durağı = bus stop
• sessizlik saatleri = quiet hours

So sessizlik saatleri is the more natural set expression for an official rule or schedule.

In sessizlik saatleri, saatleri is part of a noun compound.

Breakdown:

• saat = hour
• -ler = plural
• -i = the compound suffix on the second noun

So:

• saatleri = hours in the compound hours of silence

Important: this -i is not the accusative here. It is the normal ending used on the second word in many Turkish noun compounds.

So:

• sessizlik saatleri = quiet hours not
• sessizlik saatler which would be ungrammatical in this structure

It breaks down like this:

• ateş = fire
• yakma = lighting / burning
• yasağıyla = with the ban

Together:

• ateş yakma yasağıyla = with the ban on lighting fires

A more detailed breakdown of the last part:

• yasak = ban, prohibition
• yasağı = its ban / the ban in the compound
• yasağıyla = with the ban

So the whole phrase means that the quiet hours were announced together with the fire-lighting ban.

Yakma is a verbal noun formed from yakmak = to burn, to light.

The suffix -ma / -me can turn a verb into something like the act of doing X.

Examples:

• içmek = to drink / smoke

• içme = drinking / smoking

• yakmak = to light, to burn
• yakma = lighting, burning

In rule-like expressions, this is very common:

• sigara içme yasağı = smoking ban
• park etme yasağı = no parking
• ateş yakma yasağı = ban on lighting fires

So yakma here means the act of lighting/burning.

This is because of a common Turkish sound change called consonant softening.

The word is:

• yasak = ban

When a vowel-initial suffix is added, final k often changes:

• k → ğ

So:

• yasak
  • -ı → yasağı

That is why you see:

• ateş yakma yasağı = fire-lighting ban

This kind of change also happens in many other words:

• kitap → kitabı
• ağaç → ağacı
• renk → rengi

-yla here means with.

It is the attached form of ile:

• ile = with

So:

• yasağı ile = with the ban
• yasağıyla = with the ban

The y is a buffer consonant, used because the word before it ends in a vowel sound.

So this part means:

• yasağıyla = with the ban

Yes, they are similar, but together they form a very common expression:

• X ile birlikte
• X'le birlikte
• X'yla birlikte

This means:

• together with
• along with

So:

• ateş yakma yasağıyla birlikte = together with the fire-lighting ban

Using both gives a slightly more explicit sense of accompaniment or simultaneous announcement. It sounds natural, especially in formal or official Turkish.

Açıklandı means was announced or was made public here.

It comes from:

• açıklamak = to explain, to announce
• açıklanmak = to be explained, to be announced
• açıklandı = was announced

The ending -dı / -di / -du / -dü is the definite past tense.

So:

• açıklandı = was announced

In this sentence, the passive meaning is important: the sentence does not say who announced it, only that it was announced.

Because Turkish very often uses a singular verb with a plural subject, especially when the subject is:

• non-human
• inanimate
• part of an official statement or report

So this is normal:

• Sessizlik saatleri açıklandı. = The quiet hours were announced.

Turkish does not require plural agreement as strictly as English does in this kind of sentence.

Literally, açıklamak / açıklanmak can mean both explain and announce, depending on context.

In this sentence, because it is about rules or official information, the best meaning is:

• announced
• made public
• released

So here açıklandı is much more naturally understood as was announced, not was explained.

Yes. Turkish word order is flexible.

This sentence has:

• Sessizlik saatleri = topic/subject
• ateş yakma yasağıyla birlikte = accompanying phrase
• açıklandı = verb

You could also say:

• Ateş yakma yasağıyla birlikte sessizlik saatleri açıklandı.

That would still mean basically the same thing, but it puts more attention on the fire-ban phrase first.

In formal written Turkish, both are possible. The original sentence sounds natural and neutral.